We carried out a formal overview of the ten trials which compared the outcome of patients managed within a stroke unit with those managed in general wards. Care in a stroke unit was associated with an odds reduction for early mortality (median follow up 3 months) of 28% (95% confidence interval 8-44%; 2 p < 0.01), which was largely sustained (odds reduction 21% CI 1-37%; 2p < 0.05) at final review (median follow up 1 year). The odds reduction for a poor outcome (death or institutionalisation) at final review was 34% (95% CI 19-47%; 2p < 0.001). The mean length of stay in stroke units ranged from 61% to 133% (pooled result 96%) of that in general wards. Stroke patients managed within specialist units are more likely to be alive and living at home a year after the stroke than those managed in general wards. Stroke unit care does not apparently increase the time spent in hospital.