We studied 925 consecutive patients hospitalised with acute stroke to determine how stroke type, age, gender and risk factors influence acute, in-hospital outcome. Stroke types included carotid territory cortical or large subcortical infarction (52%), vertebrobasilar infarction (12%), lacunar infarction (11%), intracerebral haemorrhage (16%), and subarachnoid haemorrhage (9%). Mean age (mean +/- 1 SD) was 66 +/- 15 years, but patients with cerebral infarction were older than those with cerebral haemorrhage. The prevalence of hypertension, diabetes mellitus and cardiac disease increased with age across all stroke types, while the prevalence of smoking decreased with age. Mortality was 19% overall, but varied significantly between stroke types, highest in intracerebral haemorrhage (34%), and lowest in lacunar infarction (1%). Age had a marked adverse effect on mortality, independent of stroke type, the probability of death increasing by 3 +/- 0.5% per year from 20-92 years, whereas gender had no effect. Cardiac disease and diabetes were independent adverse prognostic factors (Odds Ratios 1.6 and 1.5 respectively). Cerebral haemorrhage, age, cardiac disease and diabetes all independently worsen acute stroke outcome.