A prospective, randomized, open study was performed in 199 patients at the Leyenburg Hospital comparing amoxycillin/clavulanate (AMX/CL) with cefuroxime plus metronidazole (CR/MN) in the prophylaxis of infection following gynaecological surgery. AMX/CL was given as a single dose of 2200 mg i.v. at the start of the operation. CR/MN, 750/500 mg i.v. was administered 3 times within 24 h, beginning at the start of the operation. The study group consisted of patients undergoing either a vaginal hysterectomy, a vaginal hysterectomy with cysto/rectocele repair or a secondary caesarean section. There were no statistically significant differences in demographic characteristics, duration of surgery or anaesthetic method between the two groups. Postoperatively, 10.6% of patients developed a urinary tract infection, and febrile temperatures were found in 9.0% of patients. There were no statistically significant differences between the two treatment groups. Other complications were found in less than 1% of the study population, equally distributed between the two regimens. In this study there was a low overall percentage of infection after gynaecological surgery. AMX/CL was as effective as CR/MN as a perioperative prophylactic treatment and has the dual advantage of a single dose and lower cost.