Although widely used to provide short term anesthesia, ketamine-xylazine does not always produce satisfactory anesthesia. We compared the efficacy of ketamine-xylazine to tiletamine-zolazepam-xylazine for producing surgical anesthesia in rabbits. Four of six rabbits receiving ketamine-xylazine and all of the 12 animals given tiletamine-zolazepam-xylazine were anesthetized successfully. The mean surgical anesthesia time in the ketamine-xylazine group was 35 +/- 6 minutes as compared to the tiletamine-zolazepam-xylazine group, 72 +/- 8 minutes (p less than 0.05). There was no significant difference in the interval between the injection of the different anesthetic mixtures and the loss of either the righting reflex, the jaw reflex or the toe web pinch reflex. Respiratory rates and arterial oxygen partial pressure were higher in the ketamine-xylazine group (p less than 0.05). However, in both groups arterial blood pressure and arterial PO2 were lowered, while arterial PCO2 was elevated. No nephrotoxicity occurred. Tiletamine-zolazepam-xylazine provides effective surgical anesthesia in rabbits and in many cases may be preferable to conventional ketamine-xylazine regimen.