Twenty-one adults with acute cerebellar softening confirmed by computerized tomography (CT) were divided into two groups according to clinical course. CT findings, and outcome. In the first group, consisting of 6 patients, the condition ran a progressive course, with deterioration of consciousness, signs of brainstem compression, and the appearance of hydrocephalus on CT scan. Three patients underwent surgery successfully, 2 died postoperatively, and 1 recovered spontaneously. In the second group, comprising 15 patients, the course was benign: cerebellar symptoms and signs improved without surgery, and only discrete cerebellar signs remained a month after onset.