Objectives: Emergency medical services (EMS) use by stroke patients varies from 38% to 65%. In an epidemiological study, we determined the proportion of stroke patients who used EMS, hypothesizing that demographics, stroke severity, stroke type, and location at stroke onset would be associated with EMS use. Methods: Stroke and transient ischemic attack patients were identified in a population of 1.3 million in the Cincinnati area in 1999. Patient charts and EMS records were abstracted by research nurses and reviewed by study physicians. The proportion of EMS users was computed. Logistic regression was used to test for associations with EMS use. Results: Of 3949 strokes, we excluded strokes/transient ischemic attacks that occurred in the hospital (n = 283), out of town (n = 10), during EMS transport (n = 2), and at unknown locations (n = 73). Patients with unknown EMS use (n = 301); those with missing estimated stroke severity (n = 174), prestroke disability (n = 78), race (n = 3), and stroke type (n = 3); and those younger than 18 years (n = 14) were also excluded. The remaining 3008 patients had a mean age of 74 years, 17% were black, and 45% were men. Emergency medical services was used by 1532 (50.9%) patients. Age, prestroke disability, stroke severity, hemorrhagic stroke, and stroke at work were associated with EMS use. Race, sex, and prior stroke were not associated with EMS use. Conclusion: Half of stroke patients used EMS in our population-based study. Older patients; those with greater prestroke disability, more severe stroke, and hemorrhagic stroke; and those having stroke at work were more likely to use EMS.