A prospective study was performed following 687 patients who underwent abdominal, vaginal and laparoscopic hysterectomy for benign conditions in Turku University Hospital. This study evaluates and compares infection after hystertectomy and determines risk factors associated with postoperative infection. Infective episodes were recorded during hospital stay, convalescence for 4 to 6 weeks at home and for 1 year of follow-up. Factors found to be statistically significant fur hospital-acquired infection on univariate analysis were subsequently assessed by means of multivariate analysis. During the hospital stay 23.7% of the study. population became infected, 38.1% after vaginal hysterectomy: 23.4% after abdominal hysterectomy and 3.0% after laparoscopic hysterectomy. Over half of all hospital-acquired infections were lower urinary tract infections. Infection during convalescence occurred in 19.2% of patients: 29.5% in the vaginal hysterectomy group, 17.4%. in the abdominal hysterectomy group and 16.7% in the laparoscopic hysterectomy group. One year of follow-up did not find any infection directly attributable to surgery Five factors were found to be related to in-hospital infection on multivariate analysis. These were lack of antibiotic prophylaxis, blood loss during operation, intermittent catheterization, anaemia and medication for urinary or bowel dysfunction after operation. (C) 2000 The Hospital Infection Society.