Thirty-five anesthetic events involving 15 captive addax (Addax nasomaculatus) were performed between August 1998 and February 2002 using a combination of etorphine (33.7 ± 7.9 μg/kg) and detomidine (21.9 ± 4.6 μg/kg) or a combination of medetomidine (57.4 ± 8.6 μg/kg) and ketamine (1.22 ± 0.3 μg/kg), with or without supplemental injectable or inhalant anesthetic agents. Etorphine–detomidine anesthesia was antagonized with diprenorphine (107.1 ± 16.4 μg/kg) and atipamezole (100.9 ± 42.4 μg/kg). Medetomidine–ketamine anesthesia was antagonized with atipamezole (245.3 ± 63.4 μg/kg). Animals became recumbent within 5 min when the combination of etorphine and detomidine was used and within 11 min when the combination of medetomidine and ketamine was used. Both drug combinations were suitable for use as primary immobilizing agents producing short-duration restraint and analgesia. Bradycardia was noted with both combinations. Further investigation of the cardiopulmonary effects of both combinations is warranted.