To determine the time course of both neurological and functional recovery from stroke. Prospective, consecutive, and community based. The stroke unit of a hospital in Copenhagen, Denmark. This setting receives all acute stroke patients admitted from a well-defined catchment area of 239,886 inhabitants within the city of Copenhagen. Acute treatment as well as all stages of rehabilitation are cared for within the stroke unit regardless of age, stroke severity, and premorbid condition. 1,197 patients with acute stroke. Weekly examinations of neurological deficits (using the Scandinavian Neurological Stroke Scale) and functional disabilities (Activity of Daily Living (ADL) measured by the Barthel Index) were performed from the time of acute admission to the end of rehabilitation. These evaluations were repeated 6 months poststroke. Time course of recovery was stratified according to initial stroke severity and disability. Functional recovery was completed within 12.5 weeks (95% confidence interval (CI) 11.6 to 13.4) from stroke onset in 95% of the patients. However, 80% of the patients had reached their best ADL function within 6 weeks (CI 5.3 to 6.7) from onset. The time course of functional recovery was strongly related to initial stroke severity. Best ADL function was reached within 8.5 weeks (CI 8 to 9) in patients with initially mild strokes, within 13 weeks (CI 12 to 14) in patients with moderate strokes, within 17 weeks (CI 15 to 19) in patients with severe strokes, and within 20 weeks (CI 16 to 24) in patients with very severe strokes. After these time-points, no significant changes occurred. However, a valid prognosis of functional outcome can be made much earlier. Best ADL function was reached by 80% of the patients with initially mild strokes within 3 weeks (CI 2.6 to 3.4), within 7 weeks (CI 6 to 8) of the patients with moderate strokes, and within 11.5 weeks (CI 10 to 13) of the patients with severe and very severe strokes. The time course of neurological recovery followed a pattern similar to that of functional recovery, but preceeded functional recovery by 2 weeks on average. A reliable prognosis can in all stroke patients be made within 12 weeks from stroke onset. Even in patients with severe and very severe strokes, neurological and functional recovery should not be expected after the first 5 months.