Patients undergoing biliary surgery received either 750 mg cefuroxime i.m. with the premedication and then 8 hourly for 3 days ((group A) or 1.5 g cefuroxime i.v. at the time of induction of anaesthesia (group B) or not treatment (group C). Wound infections occurred in 3 out of 35 patients in group A, 1 out of 40 patients in group B and 11 out of 39 patients in group C (group B significantly different than group C, P less than 0.05). Eight patients (23%) in group C had chest complications. Cefuroxime was effective in the reduction of wound sepsis following biliary surgery and 1.5 g i.v. administered during induction of anaesthesia is the dosage of choice. The incidence of chest infection tended to be lower in patients receiving cefuroxime but many more patients would have to be studied for a conclusive result.