Abstract Language disturbances were studied in 40 patients with well-demarcated vascular lesions of the speech-dominant hemisphere. Computerized cranial tomography was used for localization of the lesion. Special emphasis was given to the analysis of automatized speech and repetitive verbal phenomena. Subcortical infarctions with basal ganglia involvement led to transient aphasia although long-lasting abnormalities of language could be detected in these patients. Aphasia was more severe if a cortical lesion was combined with a basal ganglia lesion. Automatisms and recurring utterances occurred only with combined cortical and basal ganglia lesions. A lesion of Wernicke's area alone, without involvement of prerolandic structures or subcortical nuclei, was sufficient to produce long-lasting aphasia, whereas lesions of Broca's area alone produced only transient language disturbances. The results are compatible with a recent theory of multiple cerebral representation of function.