Aim — to present the experience in diagnosis and surgical treatment of duodenal tumors. Material and method. The study included 27 patients with different duodenal tumors: adenocarcinoma (AC, n=8), gastrointestinal stromal tumor (GIST, n=13), neuroendocrine tumor (NET, n=6). The examination included computed tomography (in 27 patients), magnetic resonance imaging (12), transcutaneous ultrasound (14), endosonography (16), esophagogastroduodenoscopy (16). All patients were operated. Conventional (18), laparoscopic (4), robot-assisted (4), endoscopic endoluminal (1) surgical interventions were performed. 17 patients were followed up from 8 months to 10 years (median 26 months). Results. According to the instrumental diagnostic methods, duodenal tumors were verified in 19 cases. Five patients with AC underwent pancreaticoduodenectomy (Whipple procedure), 2 — palliative operations (bypass gastroenteroanastomosis), 1 — explorative laparotomy. Patients with GIST underwent 3 pancreaticoduodenectomies and 10 duodenectomies: traditional (4), laparoscopic (4) and robot-assisted (2) approaches. In case of NET 3 interventions via traditional approach (pancreaticoduodenectomy, duodenal resection, tumor enucleation), 1 endoscopic endoluminal operation, 2 robot-assisted operations (duodenal resection and duodenopancreatectomy, splenectomy, distal gastrectomy) were performed. Postoperative complications occurred in 10 (37%) patients. Postoperative mortality was absent. Long-term results were analyzed in 17 patients. All patients with GIST and NET are alive without disease progression. Two AC patients are alive from those who are available. Conclusion. Duodenal tumors are relatively rare. Radical surgical intervention in accordance with oncological principles is preferred for these patients. Organ-preserving procedures may be applied depending on morphological type of tumor. Examination and treatment of patients with duodenal tumors should be carried out in specialized surgical departments.