In spontaneous cerebellar hemorrhage emergency surgical intervention is often life-saving. Clinical features and the operative results of hypertensive cerebellar hemorrhage (18 cases) were compared with those of hemorrhage caused by small angiomas (7 cases). Hypertensive hemorrhage occured most frequently in the seventh decades. Two thirds of the patients developed brainstem compression syndrome within a week from onset. One third remained awake or drowsy throughout their clinical course. Surgical removal of a hematoma was carried out in 13 patients with four deaths. Of note, two comatose patients regained consciousness after surgery, and were discharged with residual ataxia. Rupture of a small angioma occurred in younger patients. Their clinical course was sub-acute or chronic associated with focal cerebellar dysfunction. All seven surgically treated patients subsequently regained independent function. CT findings have been found helpful not only for diagnosis but also in defining appropriate therapy. Hematomas larger than 3 cm in diameter produced signs of rapidly progressing compression of the brainstem. Thereby, regardless of the cause of bleeding, emergency removal of a clot is indicated even in awake patients. Hematomas of 2 to 3 cm produced brainstem compression or prolonged cerebellar dysfunction, and occasionally require surgical decompression. Hematomas smaller than 2 cm can be managed conservatively, since they were absorbed spontaneously in three weeks without residual functional disturbances. However, in case of a young patient exploration should be performed for a probable "cryptic" angioma.