We analysed 20 cases of cerebellar hemorrhage which were diagnosed with the brain CT scan at Seoul National University Hospital from 1982 to 1984. The most frequent presumptive cause of the hemorrhage was hypertension (65% of our cases). Most of the ictus occurred during their normal daily activities. Common symptoms at the onset were vomiting, headache, vertigo, other cerebellar dysfunctions and subsquent alteration of consciousness. The patients who showed rapid deterioration of neurologic condition were fatal in outcome. The poorer the consciousness at arrival and the larger the size of hematoma or hydrocephalus at first brain CT scan, the graver the outcome. So we suggest that suboccipital craniotomy is inevitable in cases of rapid deterioration within several hours, hematoma larger than 4 cm in diameter and marked hydrocephalus on their first brain CT scan. And neurosurgical treatment will be considered in cases of aggravating tendency over 24 hrs with hematoma larger than 3 cm and/or moderate hydrocephalus on the brain CT scan.