Believing that improved therapeutic results in cases of intracerebral hematoma might be obtained by minimal invasion of the brain, we used computed tomographic-guided stereotactic aspiration in 175 of 241 patients with putaminal hemorrhage. These patients, who were treated 6 or more hours after onset, had hematomas larger than 8 ml and were unable to raise an arm and/or leg on the affected side. Craniotomy was performed in 15 other patients, most of whom were brought to the hospital with large hematomas within 6 hours of onset. The remaining patients either had mild deficits of consciousness (33 patients) or severe deficits and/or were elderly (18 patients) and were treated conservatively. Thirteen patients (7.4%) showed rebleeding after stereotactic aspiration (6 instances of major and 7 instances of minor rebleeding). Craniotomy and removal of the hematoma were required in three of these patients. Aspiration should be avoided in patients who have a tendency for bleeding, even if mild, because rebleeding occurred in 6 of 23 such patients (26%) in these study. The consciousness level improved in 66 patients (38%), was unchanged in 103 patients (59%), and was worse in 6 patients (3%) 1 week postoperatively. Motor function of the arm improved in 55 patients (31%) and was worse in 23 patients (14%). Six months after surgery, the results for the 175 patients who underwent stereotactic aspiration were: 19% excellent, 32% good, 35% fair, 7% poor, 6% dead, and 1% unknown. For the entire series of 241 patients, the results were: 24% excellent, 26% good, 31% fair, 7% poor, 11% dead, and 1% unknown.(ABSTRACT TRUNCATED AT 250 WORDS)