Multiple endocrine neoplasia (MEN) type I is a genetically inherited disorder which predominantly involves the parathyroid and pituitary glands and pancreatic islets. Symptoms relevant to each endocrine gland may be present individually or in combination, since the tumours or hyperplasia can occur either synchronously or alone. Measurement of plasma hormone levels, endocrine function tests and radiological examination are necessary to make the diagnosis. Resection of the affected glands or treatment with specific pharmacotherapy is required for control of the disease. Long-term follow-up examination is vital to detect the appearance of lesions in other endocrine glands or the development of metastases. Screening of relatives and genetic counselling are important in the management of affected families.