Objective: To determine the effect of morphine and flunixin meglumine on isoflurane (ISO) minimum alveolar concentration (MAC) in goats. Study design: Prospective, randomized experimental study. Animals: Five adult, wether goats from 1 to 3 years in age, and weighing 24-65 kg. Methods: Anesthesia was induced using ISO, which was delivered via a mask. Goats were intubated and ventilated to maintain an end-tidal carbon dioxide concentration between 25 and 30 mm Hg (3.3-4 kPa). End-tidal ISO concentration was measured using an infrared analyzer. The baseline ISO MAC that prevented purposeful movement in response to clamping a claw was determined. Following baseline MAC determination, each goat received one of the following four treatments intravenously (IV): morphine (2 mg kg-1), flunixin (1.5 mg kg-1), flunixin (1.5 mg kg-1) plus morphine (2 mg kg-1) or saline, and the MAC was re-determined. Goats were studied at weekly intervals, and each goat received each treatment in a randomized fashion. Results: The baseline ISO MAC for the control treatment was 1.43%. Morphine reduced the MAC by 29.7%. Flunixin did not significantly decrease the MAC nor did it potentiate the effect of morphine on MAC. The quality of recovery was good in all cases. Conclusions: Morphine (2 mg kg-1, IV) significantly reduced the ISO MAC in goats and did not adversely affect the quality of recovery. Clinical relevance: The use of morphine, at the dose studied, in association with ISO anesthesia, will allow a clinically significant reduction in the concentration of ISO required to maintain general anesthesia in goats.