We present a retrospective study on 63 patients who underwent decompressive craniectomy from April 1985 to June 1990. All patients were comatose(Glasgow Coma Score;3-8) at the time of operation. There were 42 males and 21 females with an age range of 7 to 80 years(mean age, 43 years). Bifrontal craniectomy was performed in 15 patients(23.8%) and frontotemporoparietal craniectomy was done in 48 patients(76.2%). Pupils were abnormal in 41 patients(65.1%) on arrival. However, those became abnormal in 60 patients(95.2%) preoperatively. Fourty nine of the 63 patients died within the first 30 days of surgery (operative mortality, 77.8%). Late mortality was 3.2%, making the total mortality for this series 81.0%. Only eight patients(12.7%) could have favorable outcome(good recovery and moderate disability). The operative method did not affect on the prognosis. The most common primary mass lesion was acute subdural hematoma(35 patient;55.6%). Skull fracture was found in 48 patients(76.2%). Postoperative CT scanning were obtained in 18 patients(28.6%). Moderate to marked degree of edema was found in 14 patients(77.8%). Delayed lesions were found in 13 patients(72.2%). Intracerebral hematoma was the most common delayed lesion. In nine patients(50.0%), the degree of midline shift was more severe than the preoperative CT scans. These results stroly suggested that the WDCE was not an effective surgical method due to its high mortality, morbidity and possible harmful effect such as enhanced edema formation and hastened delayed lesions.