We report a prospective, controlled study of the incidence of septic complications following biliary tract stone surgery. This study included a total of 280 patients operated on in eight hospitals in various European countries. In this study the computer program "Surgery" was used. Of 280 patients, 77 (27.5%) were male and 203 (72.5%) were female. The age ranged from 20 to 92 years (mean 54.8 years); 78.9% of the cases corresponded to clean-contaminated surgery; 85% of the patients received antibiotic prophylaxis with cefazolin. Twenty-one patients developed postoperative septic complications (7.5%) of which 12 (4.3%) were wound infections; five patients (1.8%) had intra-abdominal infections. The wound infection rate was 3.2% in clean-contaminated surgery, 7.7% in contaminated and 20% in dirty (p < 0.02). In laparoscopic cholecystectomy the global rate of septic complications was 3.6% vs. 12.6% in open cholecystectomy (p < 0.01); 2.4% and 6.3% wound infection respectively. The mean age of patients who developed postoperative septic complications was 61.5 years and 54.2 years old who did not develop any complications (p < 0.03). The duration of the postoperative period was 5 days in patients without infection and 13 days in patients with infection (p < 0.0001). Two patients died, one of them (0.4%) caused by sepsis. In addition to the European prospective study, a review of the problems of sepsis in biliary surgery was carried out.