In a prospective, randomised, double-blind study of 60 patients who had an elective Caesarean section under spinal anaesthesia we compared 0.1 mg intrathecal morphine with intrathecal saline placebo. All patients received morphine intravenously by patient-controlled analgesia after the operation. Pain, satisfaction and side-effects were assessed at 4 and 24 h after the operation. Pain measured by a 100-mm visual analogue scale was less in the intrathecal morphine group at both times (p <0.05) and morphine consumption was lower (p <0.01). At 4 h the intrathecal morphine group had more pruritus (p <0.001) but there was no difference in satisfaction. At 24 h there was no significant difference in side-effects, but overall satisfaction measured by visual analogue scale was better in the intrathecal morphine group (p <0.01). Intrathecal morphine improves pain relief and patient satisfaction after Caesarean section.