Gastroentero-pancreatic neuroendocrine tumours (GEP-NETs) are regarded as a fairly rare disease. They are derived from the neuroendocrine system of the gastrointestinal tract and the pancreas and share common clinical features. So far, there is still uncertainty about the cell biology and mechanistic regulation of these tumours. Therefore targeted treatment is limited and management challenging. Treatment options include surgery, medical and ablative therapy, and more recently peptide-receptor radionuclide therapy. In order to better understand the characteristics of GEP-NETs and to evaluate treatment strategies, the SwissNET registry aims at the collection of data from patients presenting with a GEP-NET in Switzerland. Data will be entered prospectively and anonymized in a specifically designed database after the patient has given informed consent. All hospitals and general practitioners are invited to report on patients with a GEP-NET diagnosis and to participate to the registry. Data will be evaluated within regular time frames, focussing on types of GEP-NETs, treatment modalities and patient outcomes (e.g. mortality, hospitalisation rate), thereby contributing to the better understanding of these tumours.