This study was designed to evaluate the maternal intraoperative and postoperative analgesia and neonatal effects of adding sufentanil to epidural anesthesia for cesarean section before the skin incision. Forty-five multipara were randomized in three equal groups to receive sufentanil 80 micrograms, 50 micrograms, or saline with the epidural lidocaine. Intraoperative and postoperative analgesia and side effects were recorded. Infants were evaluated by Apgar score at one and five minutes and by Neurologic and Adaptive Capacity Score and Early Neonatal Neurobehavioral Scale at one, four and 24 hours of life. Superior analgesia, with no intraoperative requirements for supplemental narcotics, was obtained when either 80 micrograms or 50 micrograms sufentanil were added to lidocaine. Postoperative analgesia was prolonged after sufentanil, but side effects increased with the greater dose. The infants whose mothers received 80 micrograms sufentanil showed a mild neurobehavioral depression. It is therefore concluded that the addition of 50 micrograms of sufentanil improves both intraoperative and postoperative analgesia without significant neonatal effects.