The article presents modern possibilities and existing problematic aspects of the choice of therapeutic and diagnostic tactics in patients with neuroendocrine tumors of the gastrointestinal tract and pancreas are presented. The asymptomatic course of neuroendocrine tumors of the gastrointestinal tract and pancreas was established in 18.5% and 24.6% of cases, respectively. Carcinoid syndrome was detected in 12.9%. The sensitivity rates of chromogranin A and neuron-specific enolase in the diagnosis of tumors were 54% and 13%, respectively. The levels of cancer-embryonic antigen in G-1/G-2 and G-3 tumors were 5 ng/ml and 8.9 ng/ml, respectively (p 0.001). A pathognomonic sign of neuroendocrine tumors of the small intestine is a mesentery tumor conglomerate, and the sensitivity rates of computed tomography and positron emission tomography with 68Ga to detect this sign were 92.3% and 92.9%, respectively (p 0.05). The computed tomographic density of neuroendocrine pancreatic tumors G-1/G-2 in the arterial phase was 112.1 40.2 HU and that of G-3 tumors was 54.0 10.4 HU (p = 0.025). Surgical treatment was performed in 259 (79.7%) patients. Postoperative complications that developed in localized and locally distributed neuroendocrine tumors of the gastrointestinal tract and of the pancreas were found in 3.5% and 8.8%, and in 58.1% and 40% of the cases, respectively, and those of generalized tumors were noted in 20%. The tumor-specific 5-year survival rates of patients with localized neuroendocrine tumors of the gastrointestinal tract and pancreas were 92.5% and 94.4%, those with locally distributed tumors had 66.8% and 77.8%, and those with generalized tumors had 51.8% and 47.1%, respectively. In patients with generalized tumors, the 5-year survival rates after cytoreduction and removal of the primary tumor were 88.2% and 64.6%, respectively (p = 0.097), and the rate after drug therapy was 28.8% (p 0.001). The prognosis of the 5-year survival of patients is determined by the degree of malignancy and tumor localization, treatment method, and patient age. In general, neuroendocrine tumors are a heterogeneous group of neoplasms that require a multidisciplinary approach to diagnosis and choice of therapeutic strategies.