This study is based on a series of 109 consecutive head injured patients with the CT scan diagnosis of acute subdural hematoma. The overall outcome was assessed at 6 months after injury using the Glasgow Outcome Scale. By logistic regression analysis a small set of clinical features (the best sum Glasgow Coma Scale score within 24 h after admission, and pupillary inequality) was revealed as significant prognostic features. The method described allows bedside predictions in individual future cases.