Neuroendocrine neoplasmas are a form of cancer arising from cells of diffuse neuroendocrine system. They produce peptides or amines that act as hormones or neurotransmitters. Incidence of NENs is relatively low. Diagnostic work-up and treatment requires a multidisciplinary team approach. The aim of this study was an analysis of data from patients with well-differentiated neuroendocrine neoplasmas of gastrointestinal tract. The study included patients followed up from 1998 to 2013 with histologically confirmed well-differentiated digestive neuroendocrine neoplasm with low or intermediate malignant potential. 97 patients were included; 34 men (35.1%) and 63 women (64.9%). In patients being diagnosed after 2005 interferon treatment is significantly less used than endoscopic and peptide receptor radionuclide therapy. We have identified more appropriate discriminant values of 5-HIAA and chromogranin A (6.8 mg/24 hours; 70 ng/ml) for predicting the presence of metastases at the time of diagnosis. We have identified following risk factors for overall mortality: liver metastases, presence of diarrhea, flush, small bowel primary tumor, high values of CgA and 5-HIAA at the time of diagnosis (5-HIAA > 520.52 mg/24 hours, CgA > 174.5 ng/ml). Surgical treatment was found to be a positive prognostic factor.