We developed a neuropsychological battery for assessment of cognitive processes that was standardized in 150 neurologically intact subjects from different socioeducational levels in Mexico City (Ostrosky et al., 1985, 1986). The present study was designed to explore the capacity of this neuropsychological battery to discriminate a brain-injured population from a normal one. Thirty-four patients attending the neurological service of two hospitals institutions in Mexico City were studied. The reasons for going to the hospital included both neurological and neuropsychological symptoms. The group was divided into two subgroups: twenty-four patients who showed brain damage confirmed by brain scans, and ten patients with a normal brain scan. A control group of 19 normal subjects was also studied and paired with the other groups by sex, age and sociocultural level. The results show that the neuropsychological battery was able to recognize 83.3% of the patients with scanographically confirmed brain damage: the total percentage of successful diagnosis was 88.2% and there were no false positives. These results indicate that neuropsychological assessment is a powerful diagnostic procedure that also evaluates the patient's cognitive-behavioral activity and can help to predict the possibilities for rehabilitation and return to work.