The case records of 114 patients were reviewed to ascertain the efficacy of bedside twist-drill craniotomy and continuous closed-system catheter drainage for the treatment of chronic subdural hematomas. Ninety-eight (86%) patients achieved an excellent outcome, and seven (6%) had no significant improvement. The total mortality from all cases was 8% in this group. Successful catheter drainage of the chronic subdural hematoma was accomplished by either one or two catheter placements in 102 (90%) patients. Twelve patients required additional operative procedures. The mean duration of hospitalization for the study group was 16 days. No infections occurred in these patients. Remission of the clinical syndrome did not require the radiographic resolution of the chronic subdural hematoma.