A review of the literature on sex differences in aphasia reveals contradictory findings with limited clinical relevance. To some degree, sex is reported to interact with age, localization of lesion and recovery rate. Women more often than men have fluent speech and suffer from posterior lesions. They are reported to be older and they seem to improve more on expressive tasks. In the present study a sample of left hemisphere injured aphasic stroke patients, 124 male and 80 female, was analysed for sex differences in degree and type of aphasia. A significant sex difference was found with a higher incidence of female than male patients among severely impaired fluent aphasics (Wernicke's aphasia). It is suggested that sociobiological models of differential development and the influence of sex‐role behaviour and cognitive strategies, should be given more attention in further research if explanatory models of observed sex differences in cognitive functioning and aphasia are to be develope