Herein is a review of eigthy six surgical cases from March to August, 1986 which recieved tetracaine hydrochloride spinal anesthesia. In an attempt to relieve postoperative pain, 0.5 mg morphine sulfate was administrated into the lumbar subarachnoid space. Pruritus, a side effect of intraspinal morphine, was explored in detail. The results were as follows : 1) The incidence of pruritus was 67.4%, 65.5% in man and 71.0% in woman. 2) The time of onset of pruritus was between 30 and 120 minutes with an average of 79.1 minutes. 3) Pruritus primary occurred on the face(87.9%), especially on the nasal, perinasal and periocular areas. Other sites included the scalp, neck, chest, abdomen, shoulder, hip, thigh, flank, and whole body. 4) The severity of pruritus was classified as mild and moderate, but 4 cases(6.9%) were regarded as severe and were treated with naloxone. 5) The duration of pruritus was from 15 minutes to 19 hours with an average of 4.7 hours. 6) There was no significant difference in the prevention of pruritus between the group recieving diphenhydramine and the one which received normal saline.