We conducted serial neurologic examinations on 500 patients in nontraumatic coma to identify factors predicting recovery. Overall, 81 patients (16%) led an independent life at some point within the first year; the remainder either died without recovery from coma (61%), never improved beyond the vegetative state (12%), or regained consciousness but remained dependent on others for daily activities (11%). Functional recovery did not depend on age but was to some degree related to the cause of coma (subarachnoid hemorrhage and other cerebrovascular disease having the worst recovery; hypoxia-ischemia, intermediate; and hepatic and miscellaneous causes, best) and especially to early clinical signs of brain dysfunction. Even within hours of the onset of coma, only one of 120 patients lacking two of corneal, pupillary, and oculovestibular responses ever regained independent function. The study identifies clinical features of comatose patients that appear within the first week and that are important for predicting recovery and designing future therapeutic trials.