We present three cases of epidural abscess, all in patients in whom an epidural catheter had been inserted for postoperative pain management. In all three cases the infecting organism was Staphylococcus aureus and two patients had diabetes. The diagnosis was made within 3 days of epidural catheter removal in two cases, but in one the abscess did not present until after the patient had been discharged from hospital. We have retrospectively calculated the incidence of epidural abscess in our hospital over the 5-yr period 1993-98 to be 1 in 800 (0.12%). We emphasize the importance of using techniques that minimize the risk of bacterial contamination during both catheter placement and the management of infusion, and seek to raise awareness of this relatively rare but significant condition.