Hypopituitarism is usually caused by tumours of the hypothalamus-pituitary region, but may also arise as the consequence of pituitary inflammation, infiltration or hypoperfusion. Tumour mass reduction by surgical intervention or following drug treatment may improve pituitary function. However, neurosurgical tumour resection and radiation therapy may lead to a permanent manifestation of hypopituitarism. Diagnosis is established by endocrine testing, revealing the characteristic low serum concentrations of both peripheral hormone and associated regulatory hormone of pituitary origin. Hypopituitarism may involve from one to all endocrine axes regulated by the pituitary (in order of frequency: growth hormone deficiency>secondary hypogonadism>secondary hypothyroidism>secondary adrenal failure). The treatment of permanent hypopituitarism consists of replacement of the peripheral hormones (hydrocortisone, DHEA, thyroxine, testosterone or oestradiol, growth hormone). Quality of life is impaired in a considerable number of patients with hypopituitarism and mortality is increased, mostly due to cardiovascular and cerebrovascular causes, but also as a consequence of recurrent respiratory infections. Long-term care and monitoring of patients with hypopituitarism requires the experienced endocrinologist.