Although epidural anaesthesia and analgesia are widely used in obstetrics, there are no large contemporary prospective series detailing associated complications. Prospective data was collected on all obstetric epidural blocks performed for labour and delivery in a single institution between July 1989 and August 1994. A data entry sheet was compiled and entered onto a computer database. Confidence intervals for proportions were calculated using standard methods. Information from 10 995 epidural blocks was analysed. Epidural analgesia in labour was the primary indication in 7648, and anaesthesia for caesarean section in 3311. Minor complications included failed or abandoned insertion (incidence 0.5%), reinsertion of the epidural catheter (5%), and inadequate anaesthesia (1.7%) or analgesia (0.9%). Three percent were associated with venous puncture and 0.6% with accidental dural puncture. Maternal mortality was zero. Unexpectedly high blocks occurred on eight occasions (0.07%), two requiring intubation and ventilation. Three women (0.06%) experienced mild respiratory depression after postoperative epidural opioid. There was no major local anaesthetic toxicity or neurological deficit. The incidence of potentially life-threatening morbidity was thus 0.02% although in both cases outcome was good. The only persisting complication was neurological, an apparent epidural catheter-induced traumatic mononeuropathy.