Green iguanas are found throughout tropical and subtropical climates of North and South America. In Mexico and Central America they occur as far south as Paraguay and Argentina in South America. Green iguanas have also been introduced to the Lesser Antilles and, over the past 20 years, to the Greater Antilles and southern Florida.
Depending on the region, green iguanas exhibit physical differences. Originally, the South American population was called Iguana iguana iguana. South American green iguanas proved less cold‐tolerant than the Central American iguanas once named Iguana iguana rinolopha. Today, all these subspecies are considered synonymous under a single recognized species: Iguana iguana.
Availability
The green iguana is by far the most common reptile in the pet trade today. They are easy to obtain—up to a million hatchlings are imported into the U.S. annually. While these charming lizards make cute pets, very few buyers can meet the needs of a full‐grown green iguana.
If you’re considering getting an iguana, I recommend sourcing from reputable breeders or keepers with reptile expertise rather than from ordinary pet shops. If you cannot provide adequate amenities for an adult iguana, you should not bring one home.
Currently, several attractive morphs of green iguana are available on the market—red, blue, and albino. Unfortunately, due to their high cost, blue and albino iguanas are quite rare in our country. Contrary to popular belief, albino green iguanas are not harmed by sunshine or ultraviolet light. There is no negative effect of sunlight on albino morphs. These morphs are expensive now but are likely to become more affordable over time.
Size
Green iguanas can reach 180–215 cm in total length and weigh around 9 kg. Males generally grow larger than females; although females rarely exceed 150 cm. Mature males also develop larger dorsal spines and prominent femoral pores on the underside of their hind legs.
Lifespan
With proper care, green iguanas live 15–20 years.
Habitat
A juvenile or subadult iguana around 45 cm long does fine in a 75 L terrarium. Placing a newly acquired small reptile in an oversized enclosure can sometimes make it difficult for the animal to find food and water—and larger spaces don’t reassure them you aren’t a predator! Thus, a smaller enclosure is better for young iguanas than a too‐large cage.
An adult green iguana, however, needs a tremendous amount of space. That adorable baby will swiftly grow into a two‐meter “dinosaur” with needs beyond the average hobbyist’s means.
An adult iguana requires an enclosure at least 350 cm long, 200 cm wide, and 200 cm tall. Height is especially important, as iguanas are arboreal in the wild. A good rule of thumb is to provide “twice the length” of the iguana so it can fully stretch out. Never house adult males together—they will fight. Likewise, don’t keep a male and female together unless you have separate heating, UVB, feeding stations, etc. Even in a huge pen, multiple iguanas in one cage increase aggression.
The material or vendor for the enclosure matters less once proper conditions—size, ventilation, security—are met. However, build or buy one with front‐opening doors rather than a top‐opening lid; reaching in from above can frighten an iguana.
Substrate
The best substrate is a reptile carpet sold for this purpose. It’s easy to clean and promotes hygiene.
Heat & Light
Green iguanas require significant heat. To warm the entire body, they need at least one heat lamp. At night, use an infrared lamp to avoid disturbing the animal. Position the lamp high enough so the iguana cannot get too close and burn itself.
A UVB lamp is essential for vitamin D₃ synthesis. Both UVA and UVB are required for optimal health. Strong UVB prevents metabolic bone disease (MBD); without it, iguanas develop bone deformities that shorten their lives. UVB bulbs lose effectiveness after about 6–8 months, so replace them regularly.
The basking area should reach at least 45 °C, and heat must come from above so the iguana’s parietal eye (“third eye”) can detect it. This small photoreceptive organ on the top of the head senses light, dark, and movement—vital for thermoregulation and warning of aerial predators.
The enclosure’s far end should be cooler (around 26 °C) so the iguana can thermoregulate by moving between hot and cool zones.
Never use under‐tank heating pads or heat rocks; iguanas can burn themselves because their parietal eye cannot sense heat from below. Their legs and abdomen often suffer burns. Remember these two rules: ample space and sufficient overhead heat.
Water
Fresh water must always be available. Remember that small iguanas, especially hatchlings, may not find a water dish. Mist the enclosure twice weekly to maintain humidity and to help them hydrate. Ideally, provide a water bowl large enough for the iguana to soak in—iguana feces in water also makes cleaning easier. In the wild, green iguanas live near water and are excellent swimmers.
Diet
Green iguanas thrive on leafy greens available at grocery stores or on commercial iguana diets: lettuce, arugula, dandelion greens, yellow squash, peas, etc. A small amount of fruit may be offered, but too much fruit causes diarrhea.
Feeding juvenile iguanas differs slightly from adults: chop greens into manageable pieces so they can swallow without chewing. As your iguana grows, its appetite will increase dramatically—soon you’ll be shopping daily!
Provide calcium supplements (without vitamin D₃) once weekly, and a general vitamin supplement every three weeks. Do not feed insects or high‐protein diets; excess protein leads to kidney failure and death in iguanas.
Stress
Change is hard for iguanas, especially those used to a routine. The more consistent their daily schedule, the faster they settle into a new home. Understanding stressors helps you identify and mitigate them.
There are three types of stress:
Environmental stress: issues with lighting, heating, or enclosure
Behavioral stress: changes disrupting their routine
Social stress: interactions with people or other iguanas
Stress signs include:
Increased or decreased appetite
Aggression, crankiness, lethargy
Uncharacteristic activity—hiding or staying in cold spots
Burrowing, rubbing nose, escape attempts
Changes in interaction with owners
Altered defecation habits
Darkening skin or dulling of mouth tissues
Constant hiding
Iguanas can’t tell you what type of stress they feel—you must observe behaviors and context to find causes and solutions. During shedding, stress signs may appear but will subside once the process completes.
Handling & Temperament
Baby green iguanas rarely bite, but avoid excessive handling until they acclimate. In early weeks, they may lash their tails or attempt to bite; this diminishes with age. Handle your iguana briefly each day to build trust. Always approach from below and support its body—reaching from above can be perceived as a threat.
Allow supervised free‐roaming outside the enclosure occasionally to enrich its life. However, too much freedom can lead to constant escape attempts and inadequate UV exposure. Limit roaming so they still receive sufficient UVB lighting.
Green iguanas are intelligent, sociable pets. Unlike many snakes and other reptiles, they can recognize their owners and develop distinct personalities and affectionate behaviors over time.
Please don’t acquire a green iguana just because they look cute. Sadly, baby iguanas are now so cheap they’ve become “disposable pets.” Many die due to their owners’ lack of knowledge and resources. Before purchasing, remember that iguanas are living creatures with specific needs. If, after reading this guide, you still want one, you won’t be disappointed—green iguanas are among the best reptile pets available today.
