Data from 11 observed patients with spontaneous pontine haemorrhages were compared to the findings in 235 cases reported in 9 studies. Causes of pontine haemorrhages which have an incidence of 2 to 4/100 000/year include hypertension, vascular malformations (a.v.-haemangioma, cavernous haemangioma, capillary teleangiectasies), anticoagulative treatment and inflammatory vascular disease. Diffusely spreading hypertensive haemorrhages are of apo-plectiform onset with fast developing coma, and show disturbance of vegetative function (disturbance of respiration, cardiac dysrhythmias, hyperthermia, hypertension), miosis and other neuroophthalmologic symptoms, flaccid tetraparalysis and blood-stained cerebrospinal fluid; mortality is high, reaching 50% after 24 hours and 90% after 3 weeks. Vascular malformations are the origin of circumscribed pontine haematomas with slowly progressing disturbance of consciousness and brain stem symptoms with variable course exhibiting multiple remissions and recurrences. In respect of symptomatology and clinical course, slight lateral hypertensive pontine haemorrhages must be placed between these two typical syndromes. Diagnosis of pontine haemorrhages is supported by x-ray computed tomography, but vascular malformations can be detected only by cerebral angiography. Treatment of patients with pontine haemorrhages must be based on intensive care with regular control via CT. Increased intracranial pressure and internal hydrocephalus caused by blockage of CSF passage necessitate ventricular drainage. While hypertensive pontine haemorrhages cannot be surgically treated, pontine haematomas and the causative vascular malformations can be removed.