A prospective study for the treatment of cerebellar haemorrhage was conducted in a non-selected group of 33 patients. All patients with cerebellar haemorrhage arriving at the Department of Neurosurgery at Homburg/Saar have been included in this study, also those in bad condition, with high risk factors, and the aged. All of them required intensive care respectively intensive supervision. The following management protocol has been established. I. Cases with small haemorrhage, in good clinical condition, without hydrocephalus and/or occlusion of the basal cisterns: intensive supervision, operative intervention only if they deteriorate into one of the following groups. II. Cases with hydrocephalus-even if not yet pronounced-but without occluded basal cisterns and without major tonsillar herniation: pressure monitored ventricular drainage, which opens at 15 mm Hg and thus prevents higher CSF pressure developing. III. a): Cases with large haematoma, occluded basal cisterns and/or tonsillar herniation, but without severe general risk factors, as a first step: pressure monitored ventricular drainage; as a second step, if they do not improve soon after the normalization of the ventricular pressure: open surgical evacuation of the haematoma, which also decompresses the posterior fossa. If present and possible, causative vascular malformations may be dealt with at the same session. III. b): Same intracranial situation, but patients with severe general risk factors: pressure monitored ventricular drainage only. IV. Cases with causative aneurysm or angioma, who initially had been treated conservatively or by ventricular drainage: secondary operation of the vascular malformation after stabilization of the general conditions.(ABSTRACT TRUNCATED AT 250 WORDS)