Pancreatic neuroendocrine tumours arise from cells within the endocrine pancreas (Islets of Langerhans) and consequently may manifest symptoms relating to hormone secretion in addition to local tumour effects. Hormone production is determined by the tumour cell of origin (eg insulinoma from pancreatic beta-cells), and hormone hypersecretion may be fatal if uncontrolled. Tumours may also secrete more than one hormone. Consequently, effective management of functional pancreatic neuroendocrine tumours must control the hormone syndrome (symptomatic treatment) in addition to the underlying tumour (oncologic treatment). These therapeutic principles will be discussed, with a focus on symptomatic treatments for insulinoma, gastrinoma, glucagonoma, VIPoma, somatostatinoma and ectopic ACTH syndrome using case examples.