This double-blind, randomized study of analgesia after caesarean section compared patient controlled epidural analgesia with pethidine (15 mg of a 0.25% solution and a 10 minute lockout period) versus a single bolus of epidural morphine 4 mg. Data were collected on 78 patients at 2, 6, 8, and 24 hours postoperatively and analysed using the Wilcoxon rank sum test. Satisfactory analgesia and nausea/vomiting during the first twenty-four hours did not differ between the two groups. The incidence of pruritus (P < 0.001) was lower in the pethidine group at 2, 6, and 8 hours, with no difference by 24 hours. Therefore PCEA pethidine provides a useful alternative to single-dose morphine after caesarean section, particularly in those patients who have suffered severe morphine-induced pruritus previously.