Hypnosis was used in connection with thoracotomy for heart disease in eight patients, the youngest being 10 and the oldest 58 years of age. The first six all received diphenhydramine, thiamylal, alphaprodine, either pentobarbital or secobarbital, and either succinylcholine or hexylcaine. The seventh required only thiamylal, succinylcholine, and hexylcaine. The eighth, a woman aged 42, underwent mitral commisurotomy after receiving only hexylcaine topically for endotracheal intubation and 30 mg. of succinylcholine intravenously for muscular relaxation; this patient was able to remove the tube herself, required no postoperative narcotics or sedatives, and manifested total operative amnesia. It is concluded that the reassurance which can be induced by hypnosis allays fear, anxiety, and tension more effectively than do the tranquilizing drugs.