The Barcelona Stroke Registry was established to collect clinical data of hospitalized patients with stroke, in order to study their clinical characteristics and outcome. Data were collected over a 17-year period in 3,577 consecutive patients with first-ever stroke admitted to a stroke unit in two university hospitals in the city of Barcelona (Catalonia, Spain). Patients were generally admitted within 48 h from stroke onset, were evaluated by a neurologist, and clinical data were collected using a standardized protocol. All subjects underwent computerized tomography (CT) examination. Data on the 3,577 patients revealed the following stroke subtypes: cerebral infarction (81%), corresponding to the varieties of atherothrombotic (39.5%), cardioembolic (17.5%), lacunar (11%), unusual (5%), or unknown (8%); and cerebral hemorrhage. We analyzed age distribution (mean age 66 years); risk factors (the most frequent being hypertension, present in 54% of cerebral infarctions and in 65% of hemorrhages); clinical manifestations (the most salient being abrupt onset in one half of the cases; high frequency of decreased consciousness in cardioembolic infarction; headache, seizures and nuclear palsy in 'unusual' cerebral infarctions; vomiting and coma in hemorrhage); localizations by vascular territories; mechanisms of the various stroke subtypes; complications (present in one third of patients, with a mortality of 14%), and outcome. Two out of 3 hospitalized stroke patients are first-ever stroke sufferers. Neuroimaging shows a cerebral infarct in 86.5% of cases. Clinical and laboratory investigations cannot determine the mechanism of 8% of infarcts and of 23% of hemorrhages. The high frequency of medical complications, mortality, and disability highlights the need to establish stroke units and stroke registries in order to perform further research into the diagnosis and management of patients with cerebrovascular disease.