We studied sustained attention in 64 subjects, 49 of whom had suffered a traumatic brain injury (TBI) and 15 who served as orthopedic controls. Subjects were required to respond to the appearance or disappearance of a star on a computer monitor, embedded in 250 stars. Results showed that subjects with TBI had lower accuracy than controls and a significant vigilance decrement. Severe TBI resulted in much greater attentional deficits, than mild injuries.