Neuroendocrine tumours of the gastroenteropancreatic tract (GEP-NETs) comprise a group of very heterogeneous neoplasms, which are considered 'rare diseases'. Epidemiological studies on the incidence of GEP-NETs worldwide have reported a remarkable increase in the detection of these tumours. In a recent study, based on pathology reports (PALGA) to investigate the incidence of pancreatic and duodenal neuroendocrine tumours in the Netherlands from 1991 until 2009, we also noticed a significant increase in the incidence of these tumours. In particular, the incidence of non-functioning neuroendocrine tumours had significantly increased over this period. Remarkably, a substantial discrepancy was observed between the numbers of neuroendocrine tumours diagnosed in the clinical as opposed to the pathological setting, emphasising that these tumours provide a real diagnostic challenge. To improve the diagnosis of GEP -NET s, we advocate that these complex neoplasms should receive more specialised attention. In this mini-review we provide an overview of the current diagnostic approach to GEP-NETs, and add the recent developments in establishing the diagnosis of these tumours, in order to increase knowledge and awareness of GEP-NETs among clinicians and pathologists. Early detection in order to prevent morbidity from GEP-NETs is advocated.