OBJECTIVE To determine the effects of the addition of a background infusion to patient-controlled epidural analgesia (PCEA) using meperidine for analgesia after Caesarean section. METHODS In a randomized, double-blind study, we assigned 40 patients having elective Caesarean section to receive postoperative analgesia by patient-controlled epidural analgesia (PCEA) using meperidine 5 mg.ml-1 with (group Pi) or without (group Po) a background infusion of 10 mg.hr-l. The PCEA settings (20 mg bolus, 10 min lockout interval, four-hour maximum dose 150 mg) were otherwise identical. We compared pain at rest, pain on coughing, side effects, number of PCEA demands, drug consumption and patient satisfaction between groups in the first 24 hr after surgery. RESULTS Total consumption of meperidine was greater in group Pi (median 390 mg) than in group Po (median 240 mg; P = 0.017) and the number of PCEA demands was greater in group Po (median 12) than in group Pi (median 7.5; P = 0.012). Analgesia, side effects and patient satisfaction was similar between groups. CONCLUSIONS Addition of a background infusion to PCEA using meperidine after Caesarean section has no clinical benefit.