The aim — to improve the treatment results of patients with external fistulas of duodenum (EFD) and retroperitoneal duodenal lesions of the by selecting the optimal surgical procedure and determining the most effective treatment for duodenal fistulas of different etiology.Materials and methods. The results of treatment of 29 patients (19 men and 10 women) aged from 24 to 72 years; from 2002 to 2016 with external unformed high flow complete duodenal fistulas were analyzed. In 6 patients with external unformed high flow complete duodenal fistulas, emergency surgery was performed according to urgent indications (group I). In 9 patients with damage to the II‑B part of the duodenum was formed behind the transversal colon Roux‑en‑Y anastomosis with the exception of duodenum (group II). Multi‑staged surgery was performed in 8 patients with iatrogenic lesions of the retroperitoneal descended (II‑A and II‑B) parts of the duodenum and retroperitoneal phlegmon (group III). A resection of the lower horizontal part of the duodenum was performed in 2 patients with damage of the III (lower horizontal) duodenal part, with the duodenal — jejunal anastomosis formation on the small intestine loop with stoma. In 2 patients with aortal‑duodenal fistulas after the end of the vascular stage of the operation performed resection of the duodeno‑jejunal anastomosis in front of the root of the mesentery (group IV).Results and discussion. Early surgical intervention with the gastroenteroanastomosis behind the colon transverse with duodenum disabling is consider to be the optimal treatment method for high duodenal EF, which helps to reduce the fistula elimination time and to early rehabilitation of patients. External drainage of common bile duct is considered to be a mandatory stage of surgical treatment of duodenal EF, which is developed as a result of pancreatic necrosis or iatrogenic damage during endoscopic retrograde cholangiopancreatography and endoscopic papillosphincterotomy. Early enteral probe nutrition is essential condition for adequate management of patients in the postoperative period.Conclusions. Active surgical tactics with early surgery prevent the development of purulent‑septic complications and electrolyte disorders, especially in the case of lesions of the retroperitoneal part of the duodenum. An individual approach to the choice of the method of exclusion from the passage of the duodenum in a short mono‑ or long loop allows to reduce the flow of the damaged intestine and to reduce the possibility of fatal postoperative complications.