The radiological aspect, pathology, treatment and results of 132 subdural haematomas observed in 100 patients, are discussed. The majority of these cases were characterized by a nonhomogenous CT scan picture, resulting from repeated bleeding in a previous subdural haematoma evolving to chronicity, or in a pre-existent subdural hygroma. Taking aspirin may have constituted a predisposing factor in 16% of our patients, whilst coagulation disturbances, including anticoagulant treatment, were observed in another 6%; ethylism was present in 11%. A traumatic origin was ascertained in 80% of the patients. The treatment consisted of burr hole evacuation and drainage in 91.5% of the haematomas, corresponding to 92% of the patients; it was eventually repeated once or twice in some cases. In 6% of the patients, a subduro-peritoneal drainage had to be placed ultimately and in 2%, a membranectomy had to be performed because the haematoma had become nearly completely fibrous. The necessity for repeated evacuation and eventual subduro-peritoneal drainage seems to depend mainly on a slow brain re-expansion in some elderly people, who are actually more frequently referred. Two patients died; one was deeply comatose and another in poor general condition. Morbidity in the 96 remaining patients, 2 being lost to follow-up, was 11%: 5% related to the haematoma or to the causal trauma, and 6% from other concomitant neurological disease. The functional result was satisfactory in 85%.