This study was designed to determine in postcesarean patients whether in addition to superior analgesic effects, epidural morphine administration results in secondary benefits in maternal well-being and maternal-infant interaction. Following elective cesarean section with bupivacaine epidural anesthesia, 40 healthy mothers received 5 mg preservative-free morphine sulfate in 10 ml of saline, either by the epidural (Group 1, n = 20) or the intravenous (Group 2, n = 20) route, in a randomized, double-blind fashion. Each received a simultaneous injection of saline by the alternate route. Analgesia in Group 1 lasted significantly longer (16.1 +/- 8.8 vs. 4.4 +/- 2.4 h, mean +/- SD; P less than 0.001), and morphine requirements in the first 24 h were significantly less (12.5 +/- 20 mg vs. 36 +/- 21 mg, P less than 0.001) than in Group 2. Seventy-four per cent of patients who received epidural morphine reported excellent analgesia, compared with only 32% of those who received intravenous morphine (P less than 0.05). Although Group 1 mothers ambulated 6 h earlier than those in Group 2 (P less than 0.02), there was no difference between the groups in time of first voiding, number of hours mothers slept, or duration of hospital stay. Mothers in both groups interacted with their infants equally well and for the same duration of time. Itching occurred in 58% of Group 1 patients and only 16% of Group 2 patients (P less than 0.01); the incidences of nausea, vomiting, and urinary retention were not statistically different between the groups. No respiratory depression was observed. Benefits of epidural morphine in this patient population appear limited to the provision of improved analgesia and earlier mobility.