Inroduction: Neuroendocrine tumours are relatively rare neoplasms. However, the incidence has increased over the last 20 years from approximately 2 persons per 100,000 to 4 persons per 100,000 per year. These tumours derive from the diffuse endocrine system and can be found anywhere in the body. They are classified according to their site of origin and whether they are functioning or non-functioning. There are many types of neuroendocrine tumours, including medullary thyroid cancers, paragangliomas, pheochromocytomas, bronchial carcinoids and the most common ones: gastroenteropancreatic tumours. Material and methods: We studied 16 patients with NETs admitted in our hospital between 2007 and 2012. Results: We present 16 patients, 7 men and 9 women, 52.75 +/− 20.15 year-old. One patient presented carcinoid syndrome at the time of diagnosis whereas the others presented symptoms related to primary tumours, such as abdominal pain (appendicitis) or HTA (pheochromocytoma). Location: appendix (5), ileum (3), adrenal glands (2), colon (2) stomach (1), pancreas (1), and others (2). Six patients had hepatic metastasis at the time of diagnosis. The diagnostic methods were surgery in 9 patients and CT scan in 7, and PET in 2 patients. Laboratory tests were also requested (urinary catecholamines, chromogranin, 5-HIAA), Inmunohistochemic markers were analysed in 8 patients and were positive in all of them. Treatment: In all patients surgical treatment was performed, and chemotherapy and radiotherapy were conducted in 2 patients, 1 patient treated only with Octreotide. Diagnostic: carcinoid tumours (69%), pheochromocytoma (12.5%) sporadic MEA I (12.5%), and non-fuctioning pancreatic tumour (6%). Outcome: 6 patients died during the follow-up. Discussion: The majority of NETs are carcinoid tumours. These tumours arise from enterochromaffin cells and are defined as lesions that release serotonin. Approximately 2/3 of NETs are found in the gastrointestinal tract and approximately 1/4 occur in the pulmonary tissue, with the remainder arising in other endocrine tissues. Presentation of NETs can vary widely. Patients with functioning NETs may present symptoms related to the overproduction of certain hormones, while non-functioning NETs can present symptoms such as pain, weight loss, jaundice, nauseas or vomiting. Diagnosis strategy uses blood markers and imaging, such as computed tomography, magnetic resonance image, PET or octreoscan. Treatment relies on surgery, chemotherapy, somastostatine analogues and/or radiotherapy. Conclusion: NETs are infrequent tumours, so internists must know the characteristics and diagnostic methods for a quick and efficient diagnosis.