The aim of the study was to clarify clinical and morphological criteria for prediction of treatment outcomes gastroenteropancreatic neuroendocrine tumors. Тreatment results were analyzed in 190 patients with neuroendocrine tumors of the pancreas diagnosed in 84 (44,2%), various gastrointestinal tract - 89 (46,3%), liver metastases revealed no localization of primary tumor in 17 (9.5%) of patients. It was determined that the main adverse prognostic factors of the disease are: patient age older than 60 years, tumor localization in the colon and pancreas, the index of proliferative activity (Ki-67) tumor >10%, III-IV stage oncologic process. It is shown that significant prognostic factor in patients with generalized forms of the disease is the possibility of complex treatment allowed to increase the median survival of patients with neuroendocrine tumors 2 times and neuroendocrine carcinomas 2.7 times. The findings suggest that the presence of established clinical and morphological criteria of adverse prognosis of neuroendocrine tumors is advisable a more aggressive treatment option to improve long-term results of treatment and quality of life of patients.