Postoperative complications after 8168 reoperations were seen in 143 (1.8%) patients. Clinical symptoms, laboratory tests, results of x-ray and ultrasound examinations were taken into account in diagnosis of the complications. Differential diagnosis of postoperative peritonitis, stable paralytic intestinal obstruction, early adhesive obstruction and intraabdominal bleeding based only on clinical data is difficult in many cases. Ultrasonic examination and laparoscopy permitted to reduce number of unjustified relaparotomies. In the majority of cases relaparotomy was considered as a method of choice in treatment of these complications. Mini-invasive surgeries may be performed only in mild complications. Lethality in the treatment of postoperative complications after relaparotomy was 39.4%, after laparoscopic surgeries--8.8%, after US-assisted drainage--0. General lethality was 29.4%.