We examined a series of 200 consecutive patients with spontaneous intracerebral hematoma clinically and by computed tomography, excluding patients with trauma, aneurysm, or tumor. Hematoma volume varied from 1 to 230 (average 35) ml, and overall mortality was 30% (60 patients). Of the 200 patients, 14% (28) were receiving anticoagulants; among these 28 patients hematoma volume averaged 72 ml and mortality 57% (16 patients). The 140 survivors were followed for 2-24 months. Our findings indicate that anticoagulation therapy after previous cerebral infarction or embolism of cardiogenic origin did not predispose to intracerebral hemorrhage. Prognosis was poor when the initial level of consciousness was low and the hematoma volume exceeded 50 ml in combination with dilatation of the contralateral ventricle. An intracerebral hematoma of greater than 80 ml volume was always fatal, regardless of therapy. With volumes of 40-80 ml, early surgical evacuation of the lobar hematoma may improve outcome.