Season 1: 1998–1999
| Episode Name | Airdate | Description | Location |
|---|---|---|---|
| Pilot | Unknown | The Thornberrys get word that the only way to save the funding for their show is to film a segment about the black rhino, but Donnie bites the rhino's tail and causes it to charge.
| Kenya |
| Flood Warning | September 1, 1998 | Things turn bad when Eliza discovers that the pride of lions she joins decides to hunt Debbie. | Tanzania |
| Dinner With Darwin | September 3, 1998 | Darwin is captured by a stone age tribe. | Manaus, Brazil |
| Bad Company | September 8, 1998 | A swarm of marmosets overrun the Thornberrys camp, and it's up to Eliza to beat them at their own game. | Manaus, Brazil |
| Gold Fever | September 10, 1998 | Eliza and Debbie find a chest of gold. | Galapagos Islands |
| Matadi or Bust | September 15, 1998 | On a boat trip to Matadi, Eliza attempts to free a hippo from Kip O'Donnel and Neil Biederman (the Thornberrys had met the villains prior to the series). | Matadi, Democratic Republic of the Congo |
| Temple of Eliza | September 17, 1998 | Eliza becomes a princess of Jaguars. | Manaus, Brazil |
| Vacant Lot | September 22, 1998 | Kip and Biederman are tearing down the forest and Eliza rallies the local animals in rebellion. | Brazil |
| Only Child | October 1, 1998 | Eliza is afraid that Debbie's new friend is a dolphin dressed as human. | Brazil |
| Iron Curtain | October 6, 1998 | Eliza attempts to help a young elephant escape a nature reserve and reunite with her mother. | Ngorongoro Crater, Tanzania |
| Valley Girls | October 13, 1998 | In the hands of Debbie and Eliza, the comvee is accidentally driven into a mire of mud. | Uganda |
| Naimina Enkiyio | October 22, 1998 | Eliza disregards a Masai legend about a cursed forest in which a girl gets lost. | Ngorongoro Crater, Tanzania |
| Blood Sisters | October 27, 1998 | With Nigel and Marianne off exploring bat caves, Eliza and Debbie are left at the "eerie" residence of colleague Dr. Spinoza. | Peru |
| Eliza-cology | November 5, 1998 | Eliza and Darwin accidentally disrupt the food chain in the Galapagos Islands. | Galapagos Islands, Ecuador |
| Flight of the Donnie | November 17, 1998 | Donnie is taken in by a Peruvian condor after Eliza neglects responsibility for looking after him. | Peru |
| Lost and Foundation | March 16, 1999 | Nigel takes an embarrassing home video of the girls to a presentation by mistake. | Sumatra, Indonesia |
| Nigel Knows Best | March 18, 1999 | Nigel and Eliza travel trough Peru with a llama. Meanwhile , Debbie tries to calm her mother who is concerned about her last package. | Peru |
| The Great Bangaboo | March 23, 1999 | Eliza discovers The Great Bangaboo, a magician who can talk to animals just like her. Or can he?... | Borneo, Indonesia |
| Rumble in the Jungle | March 25, 1999 | Eliza convinces a group of macaques to stand up to their enemies, Darwin unknowingly helps a different group with the same problem. | Borneo, Indonesia |
| The Dragon and the Professor | March 30, 1999 | Eliza will stop at nothing to get a look at the gigantic, fierce Komodo dragon. | Indonesia |
| Born to Be Wild | April 1, 1999 | Eliza and Darwin find a hairy Rhinoceros and try to hide it from Nigel. | Sumatra, Indonesia |
Season 2: 1999
| Episode Name | Airdate | Description | Location |
|---|---|---|---|
| Rebel Without a Trunk | August 16, 1999 | Eliza and Marianne ride elephants to a festival, but Eliza's ends up burning down their camp. While the rest of the family throws a party. | India |
| Pal Joey | August 17, 1999 | Eliza baby sits a hyper joey. Meanwhile, Debbie has a prom simulation. | Tasmania, Australia |
| Rain Dance | August 18, 1999 | The comvee breaks down in the desert, and the family is running out of water. | Namibia |
| Darwin Plays the Palace | August 19, 1999 | Darwin is captured by Kip and Biederman and sold to a prince for entertainment. | Sholapur, India |
| Stick Your Neck Out | August 23, 1999 | Eliza tries to take the place of a giraffe that was looking out for lions for a heard. | Serengeti Plain, Tanzania |
| No Laughing Matter | August 24, 1999 | Eliza frees a hyena that's never lived in the wild. | Serengeti Plain, Tanzania |
| Chimp Off the Old Block | August 25, 1999 | Darwin brings Eliza to his old troop, where Eliza has a hard time adjusting, while Debbie searches for ingredients to make shampoo. | Democratic Republic of the Congo |
| Koality and Kuantity | August 26, 1999 | Kip and Biederman capture Koalas and Eliza tries to save them. | Melbourne, Australia |
| Chew if by Sea | August 30, 1999 | Eliza befriends a wombat in Australia and when they go to India the wombat sneaks aboard. | Australia and India |
| Clash of the Teutons | August 31, 1999 | The Thornberrys run into competing documentarians and discover that they mistreat animals. | Great Dividing Range, Australia |
| You Ain't Seen Nothin', Yeti | September 1, 1999 | Eliza tries to find proof of yetis in Nepal. | Nepal |
| On the Right Track | September 2, 1999 | Kip and Biederman are laying out traps on a race track so they can win. Meanwhile, Debbie makes friends. | Finland |
| Polar Opposites | September 6, 1999 | A polar bear is blamed for crimes it did not commit. Meanwhile, Debbie gets a job to pay for a shirt. | Greenland, Denmark |
| Two's Company | September 7, 1999 | Two surviving tortoises are the last chance before the extinction of a species. | Yasuni National Park, Ecuador |
| Show Me the Bunny | September 13, 1999 | Eliza tries to protect a rabbit from a stoat. | Norway |
| Reef Grief | September 14, 1999 | Eliza and Nigel crash the commvee into the Great Barrier Reef. | Australia |
| Thornberry Island | September 15, 1999 | The family becomes stranded on a desert island. | Uncharted Island in the Bay of Bengal |
| Dances With Dingoes | September 16, 1999 | Debbie catches Eliza talking with dingoes. | Uluru, Australia |
| Tamper-Proof Seal | October 19, 1999 | A large seal won't let the Thornberrys into the commvee. | Alaska, USA |
| You Otter Know | October 20, 1999 | Kip and Biederman accidentally create an oil spill that endangers a group of otters. | Kamchatka Peninsula, Russia |
| Have Yourself A Thornberry Little Christmas | November 29, 1999 | Eliza gives away Christmas presents and decorations to protect animals, while Debbie searches for alien writing. | Namib Desert, Namibia |
Season 3: 2000-2001
| Episode Name | Airdate | Description | Location |
|---|---|---|---|
| Luck Be an Aye-Aye | February 15, 2000 | The commvee is falling apart and an aye-aye found inside is hunted and thought to be the cause. | Madagascar |
| The Kung and I | February 16, 2000 | To Eliza's dismay, Debbie is given much attention after she speaks an African language. | Kalahari Desert, Botswana |
| Dear Diary | February 17, 2000 | Eliza reads Debbie's diary, and this ensues the sisters having a feud as well as being trapped in a cave. | Cuzco, Peru |
| Black and White and Mom All Over | February 21, 2000 | A panda baby thinks that Debbie is his mother. | Chongqing, China |
| A Tiger by the Tail | February 22, 2000 | A tiger attacks Eliza by accident. | Russia |
| Forget Me Not | February 24, 2000 | Nigel looks for an elephant he saved from poachers, only to find her within her dying days. | Mt Kilimanjaro, Kenya |
| Song for Eliza | February 25, 2000 | Whales in Hawaii are disrupted when Debbie's boombox falls underwater. | Kahoolawe, Hawaii |
| Gift of Gab | February 26, 2000 | Eliza recounts how she first gained her ability to talk to animals. | Nigeria |
| Bogged Down | March 6, 2000 | Nigel is poisoned when filming with Eliza. | Philippines |
| Monkey See, Monkey Don't | March 6, 2000 | Eliza is tricked into feeding all of the food from the commvee to "sacred" monkeys. | Karnataka, India |
| Where the Gauchos Roam | March 13, 2000 | Eliza and her family are horse-back riding with old friends. | Argentina |
| A Shaky Foundation | March 13, 2000 | The Thornberrys are visited by a Foundation member, who manipulates everything. | Victoria Falls |
| Cheetahs Never Prosper | March 20, 2000 | It's the end of the dry season and Eliza tries to protect a cheetah cub. | Uganda |
| Gobi Yourself | March 20, 2000 | Eliza and her pen pal switch places for a day. | Mongolia |
| Every Little Bit Alps | March 27, 2000 | Eliza is reluctant to admit to a friend that she doesn't snowboard. | Switzerland |
| Pack Of Thornberrys | March 27, 2000 | Eliza is playing with wolves and Debbie is applying for boarding school. | Yellowstone National Park, Wyoming |
| Dragon Me Along | September 12, 2000 | Eliza recognizes some pandas and tries to save them from poachers. | China |
| Time Flies | September 19, 2000 | Debbie and Eliza explore the Everglades, but drop Nigel's birthday present into the swamp. | Everglades, Florida |
| Horse Sense | September 26, 2000 | Eliza picks a horse to race with after talking to it, and Debbie takes up archery. | Mongolia |
| Tyler Tucker, I Presume | October 2, 2000 | Eliza and Debbie lose control of the commvee and it goes into a ravine just in time for their cousin Tyler to arrive. | Democratic Republic Of The Congo |
| Critical Masai | October 3, 2000 | Eliza and Tyler compete to see who would be a better warrior. | Masai Steppe, Tanzania |
| Queen of Denial | October 4, 2000 | Eliza and Tyler find an underground chamber. | Siwa Oasis, Egypt |
| Island Trade | October 5, 2000 | Debbie, Eliza, and Tyler go to a trading post and accidentally trade the commvee for a dress. | Zanzibar, Tanzania |
| Birthday Quake | October 6, 2000 | Tyler's parents are coming to pick him up and take him out of Africa when there is an earthquake on his birthday. | Tanzania |
| The Legend of Ha Long Bay | October 10, 2000 | Eliza is convinced she saw a dragon or sea monster. | Ha Long Bay, Vietnam |
| Spirited Away | October 28, 2000 | Debbie accidentally bakes a valuable ring into bread and has to try and recover it. | Oaxaca, Mexico |
| A Family Tradition | November 22, 2000 | Eliza and Debbie are dying to spend Thanksgiving with their grandmother Sophie. | Ankarana Reserve, Madagascar |
| Happy Old Year | December 27, 2000 | Debbie goes volcano hunting, and Eliza is reunited with Santusa. | Ecuador |
| Happy Campers | December 30, 2000 | Eliza and Nigel are forced to stay behind after border guards inform them that only two people can cross to the palace. | Bhutan |
| All Work and No Play | January 12, 2001 | Debbie and Eliza's negligence causes the commvee to sink in a flash flood. | Lake Baikal, Siberia |
| New Territory | January 12, 2001 | The family breaks down in Australia and Eliza goes exploring with a handicapped 12-year-old girl. | Kakadu National Park, Australia |
| Operation Valentine | February 14, 2001 | Eliza has appendicitis on Valentine's Day, and the commvee and mini-comm are immobile. | Australia |
| Hello, Dolphin! | February 19, 2001 | Debbie goes swimming with Eliza and some dolphins after being dumped. | Shark Bay, Australia |
| April Fool's Day | April 1, 2001 | Eliza and Tyler try to prank each other. | Okavango Delta, Botswana |
| Gem of a Mom | May 10, 2001 | Eliza and Debbie struggle to find Mother's Day gifts. | Karakoram, Pakistan |
| The Anniversary | May 14, 2001 | Marrianne's parents surprise them in Japan on their anniversary. | Mt Fuji, Japan |
Season 4: 2001–2002
| Episode Name | Airdate | Description | Location |
|---|---|---|---|
| The Origin of Donnie (1) | August 18, 2001 | Donnie goes missing after he taunts crocodiles and gets shouted at by Eliza. Meanwhile Marrianne and Nigel go in search for an orangutan, and Marrianne's mother, Sophie, comes to visit. | Borneo |
| The Origin of Donnie (2) | August 18, 2001 | The search for Donnie continues while Donnie finds orangutan parents for the time being. In the meantime Marriane has broken her wrist and Nigel has a hurt knee but they carry on looking for the orangutan, and Debbie and Sophie find themselves in a tribe. | Borneo |
| The Origin of Donnie (3) | August 18, 2001 | A fire breaks out in the forest and Donnie is blamed; can Eliza convince it wasn't Donnie and get the animals to safety? Meanwhile, Marrianne and Nigel find shelter in a cave nearby, only to get lost inside, and Debbie and Sophie help the village put out the fire. | Borneo |
| The Origin of Donnie (4) | August 18, 2001 | The rest of the fire is put out by rain, the others are reunited and Donnie is found. The family believe he is going back to his parents, but they soon realize the truth. | Borneo |
| The Trouble With Darwin | October 31, 2001 | Jane Goodall tells Eliza she shouldn't have domesticated Darwin. | Tanzania |
| Hot Air | June 1, 2002 | Eliza and Darwin fight and Eliza gets stuck in a hot air balloon. | New Zealand |
Season 5: 2003–2004
| Episode Name | Airdate | Description | Location |
|---|---|---|---|
| The Wild Snob-Berry | February 3, 2003 | Shane G starts traveling with the Thornberrys. | Denali National Park, Alaska |
| Ice Follies | February 4, 2003 | Shane and Eliza are saved by Debbie after their canoe capsizes. | Glacier Bay National Park, Alaska |
| Fool's Gold | February 5, 2003 | Debbie, Shane, Darwin, and Eliza go to a fool's gold mine shaft but are separated after the exit collapses. | Yukon-Charley Rivers National Park, Alaska |
| Clash and Learn | February 6, 2003 | Eliza's friend Kit becomes better friends with Shane. | Bethel, Alaska |
| Sir Nigel (Part 1) | March 30, 2003 | Nigel will become a knight but that means that he must leave his job. | Cairngorm, Scotland |
| Sir Nigel (Part 2) | March 30, 2003 | Eliza tries to save eagles and stop her family meeting Queen Elizabeth II. | Cairngorm, Scotland and England |
| Look Who's Squawking | April 4, 2003 | Eliza tries to save a penguin, but makes everything much worse. | McMurdo Station, Antarctica |
| Eliza Unplugged | June 11, 2004 | Series Finale: Eliza trys to work up the courage to tell Shane how she feels before he leaves. Meanwhile Marianne is trying to spend time with the girls thinking that they're growing up and soon won't need her. | Behm Canal, Alaska |
