Anesthetic and cardiopulmonary effects of butorphanol administered pre- versus postoperatively were determined and compared in 11 adult Hispaniolan Amazon parrots (Amazona ventralis) anesthetized with sevoflurane and subjected to coelomic endoscopy for gonadal evaluation. Birds were randomly assigned to receive butorphanol tartrate (2 mg/kg IM) either 20 minutes before induction of anesthesia with sevoflurane (B-S group) or immediately after sevoflurane anesthesia (S group). No differences in induction or recovery times were seen between groups. Heart rates of birds in the B-S group were significantly higher at 30 minutes compared with baseline and with heart rates of birds in the S group. Birds in the S group had significantly lower heart rates at both 15 and 25 minutes compared with baseline values. Respiratory rates throughout the study were significantly lower in both groups compared with baseline values. Birds in the B-S group had significantly lower respiratory rates at baseline and after 1 minute compared with birds in the S Group. The SpO₂ and EtCO₂ values did not change significantly over time within either group, and no significant changes were present between groups. Administration of preoperative butorphanol (2 mg/kg IM) as part of a preemptive analgesic regimen appears safe and effective and will not cause clinically significant changes in anesthetic and cardiopulmonary parameters in Hispaniolan Amazon parrots anesthetized with sevoflurane.