Ninety-three aphasics were studied with repeated language assessment by a scorable test (the Western Aphasia Battery). Recovery rates were determined by measuring language performance (Aphasia Quotient) at nought to forty-five days post-onset, and three, six and twelve months and yearly after. Recovery rates were higher in post-traumatic than in cerebrovascular cases. When the stable infarcts were separately studied, the greatest recovery was seen in "Broca's" aphasics, followed by the "conduction" group. Anomic aphasia appeared to be a common end-stage of evolution. Long-term follow-up (twelve months or more) demonstrated that global aphasics have a poor prognosis, while Broca's and Wernicke's have an intermediate one. Complete recovery occurred frequently among anomic, conduction and transcortical aphasics and in more than half of the traumatic cases. Initial severity and outcome correlated significantly. Age and rate of initial recovery showed a trend of negative correlation; younger patients recovered better, but there were frequent exceptions, depending on other factors, such as the initial severity of aphasia. Although some cases recovered exceptionally well while under therapy, there was no significant difference between the treated and untreated groups, where such a comparison was possible.