Men who sustained penetrating head injuries resulting in nonfluent aphasia within six months following injury, were examined fifteen years later and classified into two groups, 13 with persistent nonfluent aphasia, and 26 without symptoms of aphasia. Relative to a normal control group on a comprehensive battery of speech and language tests, the chronic nonfluent aphasics demonstrated syntactic processing deficits in all language modalities, with only mild or no impairment in other language faculties. The recovered group demonstrated deficits only in written expressive syntax. The CT lesions of the two groups differed in the extent of left hemisphere lesion volume and the degree of posterior and deep lesion extension within the left hemisphere. The nonrecovered group did not have greater right hemisphere damage. Broca's area was equally involved in 77 per cent of patients in both groups. All patients in the nonrecovered group had posterior extension of their lesions in Wernicke's area with some involvement of the underlying white matter and basal ganglia in the left hemisphere.