Green iguanas, Iguana iguana, are a species of lizard kept in captivity for many years. Proper understanding of their biology, temperature requirements, diet and behavior is necessary for their proper husbandry, management, and veterinary care. This case report describes the treatment of a four-month-old green iguana that was brought to the Avian and Exotic Pet Unit, Madras Veterinary College, with symptoms of dehydration, emaciation, and malnourishment due to poor husbandry and management conditions. The iguana was given oxygen therapy, warm fluid therapy, and a warm cloth coverage to stabilize its condition. It was also orally given multivitamin syrup and oral rehydration powder, and advised to have ad libitum water and everyday exposure to sunlight for one to four hours. The iguana showed complete recovery after a month. Reptiles have a unique biology, metabolism, and behavior, which require special care in emergency and critical care situations. Basic principles in emergency and critical care remain the same for all reptile species, but special care needs to be considered based on their biology, metabolism, and behavior. Proper hydration and body temperature are crucial for nutritional supplementation to avoid potentially fatal "refeeding syndrome". Ensuring proper husbandry, management, nutrition, and housing are essential for the well-being of captive-bred green iguanas