Clinical features of cerebellar infarction in the territory of the superior cerebellar artery (SCA) were investigated in six male patients, ranging in age from 50 to 69 years. In all patients, there were MR images of infarction located in the area supplied by the SCA. The lesion was on the left-side in 2, right-side in 3 and bilateral (recurrent) in 1 patient. The onset of disease occurred with nausea, vomiting and floating sensation, with no overt brain stem signs other than symptoms of unilateral cerebellar ataxia and dysarthria. Five of the 6 patients had heart disease and cerebral angiography without definite evidence of SCA occlusion, strongly suggesting occlusion of the artery at its periphery due to cardiogenic embolism. A comparison of these 6 patients with those reported previously in Japan suggests that patients with SCA occlusion may be divided into two distinct subgroups: one manifesting diffuse brain stem signs in addition to cerebellar signs, and the other showing cerebellar signs as the only neurologic manifestation. In the former group, comprising the vast majority of patients, SCA occlusion occurred at the origin of the vessel due to a thrombus under a state of hypertension, diabetes mellitus or malignancy, producing signs of brain stem involvement, such as dissociating sensory disturbance and Horner's sign. While in the latter group, which included these 6 patients, paucity of brain stem signs, absence of definite cerebral angiographic evidence of SCA occlusion, and the presence of heart disease were distinguishing clinical features. Cardiogenic cerebral embolism was probably the underlying pathology in many of the cases and the functional prognosis was favorable.