This study was designed to measure recurrent stroke rates and identify their determinants in a mixed ethnic population. A cohort of 299 patients (110 black, 57 Hispanic and 132 white) admitted to a large urban hospital with an acute stroke between November 1, 1991, and July 1, 1993, was followed for a mean of 17.8 months. Demographic and historical data and stroke subtype and severity were recorded at the time of the index stroke. The main outcome measure was stroke recurrence. The unadjusted relative risk of stroke recurrence for blacks, relative to white, was 2.0 (95% CI: 0.9-4.4) and for Hispanics, relative to whites, it was 2.6 (95% CI: 1.08-60). Ethnicity appeared to be associated with recurrence risk only among first-ever strokes: the risk for blacks, relative to whites, was 2.4 (95% CI: 1.02-5.5) and for Hispanics it was 2.9 (95% CI: 1.2-7.4). None of the other putative risk factors for stroke recurrence identified at the time of initial hospitalization were associated with risk of recurrence.