This study compared the efficacy of isoflurane, sevoflurane, and desflurane in achieving hemodynamic stability in spinal procedures using moderate levels of controlled hypotension. After obtaining ethics committee approval and written informed consent, 32 American Surgical Association I-II patients were randomly allocated to receive isoflurane (n = 12), sevoflurane (n = 10), or desflurane (n = 10) in O-2-N2O (1:1) for maintenance of anesthesia. The induction of anesthesia, fentanyl dosage, and initial and maintenance volume replacements were standardized. Blood pressure was invasively monitored and maintained within a target systolic blood pressure (SBP) range of 80 to 90 mm Hg during the study. SBP outside this range was recorded. Volatile anesthetic concentration was adjusted according to the same protocol for all 3 agents. SPB control was maintained better with sevoflurane and isoflurane than desflurane; median SBP was outside the target range during 32% (range, 15%-55%) of study time with isoflurane, 26% (12%-42%) with sevoflurane, and 44% (20%-80%) with desflurane. Total blood loss did not differ among the groups. Sevoflurane and isoflurane administered in 2 L/min fresh gas flow were more effective than desflurane in achieving controlled hypotension in spinal surgery.