This thesis is an investigation of the use of isoflurane and butorphanol in the green iguana ('Iguana iguana'). Controlled studies assessing the clinical use of anesthesia and analgesics in the green iguana, a popular pet, are necessary to promote competence and confidence in providing safe, humane anesthetic management. The primary goals of this research were: (1) to estimate the anesthetic dose of isoflurane required (MAC), with and without butorphanol analgesic supplementation, (2) to evaluate the cardiovascular effects of isoflurane alone and in conjunction with butorphanol at various anesthetic depths and (3) to estimate the cardiac anesthetic index during isoflurane anesthesia (with and without butorphanol) as a relative measure of safety. From our experimental results, we estimated the MAC of isoflurane to be 2.1% and demonstrated a dose dependent depression of cardiovascular function, similar to that observed in other animals. Butorphanol had no significant effect on MAC. Some individuals had a MAC had a reduction while others had an increase in MAC, as shown in some other species. The cardiovascular effects of butorphanol and isoflurane were similar to that observed for isoflurane alone, providing evidence for the safe use of butorphanol during isofurane anesthesia. Interestingly, we found isoflurane with or without butorphanol was unable to create cardiac arrest in healthy green iguanas when increased to 9.2% over at least 2.5 hours of anesthesia. Anesthesia with isoflurane appears to be extremely safe in the green iguana. These results encourage the use of anesthesia for surgical and diagnostic procedures in the iguana. Although we were unable to show an overall advantage of butorphanol use during isoflurane anesthesia in this species, we showed no detrimental effects that can be used to argue against appropriate analgesia provision in the green iguana.