The authors reported 100 cases of acute subdural hematomas confirmed by operation from Jan. 1972 to Sept. 1975. We discussed the relationship of the type of operation to mortality in acute subdural hematomas. The types of surgical operations were divided in 4 groups. The surgical mortality rate was 19% for frontotemporoparietal craniotomy, 29% for multiple burr holes technique, 42% for craniectomy and 48% for subtemporal decompression with burr holes and total over-all mortality was 36% in our cases. The authors reviewed the literatures described the surgical operative method and it's mortality and so we thought large frontotemporoparietal craniotomy is more valuable method for operation of the acute subdural hematomas.