A technique of general anesthesia using phentanyl, a potent analgesic, and dehydrobenzperidol, a butyrophenone derivative, intravenously, together with the inhalation of nitrous oxide has been utilized to anesthetize 400 patients for general surgical procedures. The method affords excellent analgesia and hypnosis for operations not requiring muscular relaxation. For the latter a relaxant must be added. Circulatory stability was impressive during and after operation. Respiratory depression resembled that seen when other narcotic analgesics are used as adjuvants to anesthesia, but was of lesser duration than with most. Rigidity of skeletal muscles, occasionally making pulmonary ventilation difficult but responding promptly to small doses of relaxants, was seen primarily when excessive amounts of the mixture had been given by vein. Profound analgesia, minimal hypotension, probably protection against epinephrine-induced ventricular arrhythmisa, and a smooth postoperative course constitute some of the appealing features of this technique with nonexplosive agents which appears to merit further exploration.