In a prospective, randomized, double-blind clinical trial, we compared the efficacy of propofol and naloxone for the treatment of spinal-morphine-induced pruritus. Forty patients presenting with severe pruritus within 24 h of epidural morphine administration were allocated to receive either propofol 10 mg intravenously (i.v.) or naloxone 2 micrograms/kg. In the absence of a positive response, a second dose of the same treatment was given 5 min later. Pruritus and the level of post-operative pain were assessed every 5 min up to the end of the study period (45 min) using a verbal rating scale. The overall success rate in treating pruritus was similar in the two groups (80%). The rate of success after the first injection of the treatment drug was also similar (55%). The level of postoperative pain decreased after drug treatment in six patients (30%) in the propofol group versus none in the naloxone group (P < 0.05). Forty-five percent of the patients in the naloxone group had an increase in the level of postoperative pain versus none in the propofol group (P < 0.05). In conclusion, these results suggest that propofol and naloxone are equally effective in treating spinal-morphine-induced pruritus. However, the level of postoperative pain is significantly less in the propofol group.