In the wild, Green Iguanas will eat mostly plants - such as leaves, grass, and fruit. In captivity, feed any combination of the following foods twice a day: beet greens, bok choy, chard, cilantro, collard greens, dandelion greens and flowers, hibiscus flowers and leaves, escarole, grape leaves, kale, endive, mulberry leaves, mustard greens, parsley, rose petals, snow peas, spinach (sparingly) and turnip greens. A diet consisting of combinations of these foods is nutritionally complete. Lettuce is not recommended because it does not contain many nutrients, consisting mostly of water. Vitamin supplements are unnecessary, and in fact are often harmful. Water should be available at all times. In addition to the base diet one fruit flavored Tums should be crushed up and sprinkled over greens at least once a week. The Tums helps to provide needed calcium. With Iguanas it is best to avoid calcium supplements containing vitamin D3 as it may accumulate in the body, causing vitamin D3 overdose.

Lighting is another very important part of good Iguana care. They should have both fluorescent lighting (UV source) and incandescent lamps (heat source). The fluorescent light should be within 18 inches of the Iguana's body with no glass or plastic between it and the iguana. This light should be left on for 8 to 12 hours a day. Make sure whatever brand of UV bulb you choose provides both UVB and UVA light. Some "full spectrum bulbs" only provide UVA light. UVB light is needed for the iguana to produce Vitamin D3. If they do not get proper light to produce Vitamin D3 they cannot absorb calcium and may develop Metabolic Bone Disease. Ideally you should take your iguana outside for at least 30 minutes a day if weather permits. Some keepers use a leash when they bring their iguana outside, however leashes often damage their beautiful spikes causing injury. For this reason, an outdoor basking area is usually recommended. It is important that the outdoor basking area have access to shade so that the Iguana can move into cooler temperatures when needed. The incandescent light is important to provide enough heat for the Iguana's basking area. It should provide enough heat to make a basking spot that ranges between 85 and 95 degrees Fahrenheit. This light should be left on 6 to 10 hours a day. Daytime temperatures throughout the enclosure should range between 80 and 95 degrees, at nighttime lower temperatures to between 75 and 82 degrees Fahrenheit. Maintaining humidity within a tropical range is also very important, and sadly often neglected by inexperienced keepers. Many experienced owners recommend using a humidity gauge to easily monitor the level in their enclosures.

When setting up your Iguana's enclosure be sure to use a good substrate. Bark, pine chips, cedar chips, corn cobbettes, kitty litter, etc. do not make good substrates for an iguana enclosure. Iguanas "taste" their surroundings all the time with their tongue and accidentally ingest such products. As well as being life threatening, surgery for removal of impaction is VERY costly, and happens all too often for no good reason - it's preventable! Newspaper and indoor-outdoor carpet with the edges melted to prevent fraying are good substrates. Items such as hot rocks are not recommended because they can cause injury to iguanas and other reptiles. Finally, a climbing branch is also another important thing to keep inside their enclosures.