A prospective controlled trial of drainage after cholecystectomy has been carried out. In a consecutive series of 143 patients undergoing cholecystectomy, 50 patients were randomly allocated to a drainage group and a further 50 patients to a non-drainage group. The remaining 43 patients were drained electively because the common bile duct was explored or because of infection or incomplete haemostasis. There was no significant difference in the incidence of wound infection or other complications between the drainage and the non-drainage groups. The duration of postoperative pyrexia, the number of analgesic injections and the length of postoperative hospital stay were the same in both the randomized groups. One patient in the randomized drainage group had a reactionary haemorrhage from the drain site requiring transfusion. There was no mortality but one patient in the elective drainage group had to be re-explored for a subhepatic abscess. Three patients in this group drained bile from the drain for 3-9 days but all had a T tube in place. This trial fails to demonstrate any advantage or disadvantage in draining the gallbladder bed after cholecystectomy.