Background The use of thrombolytic therapy for patients with myocardial infarction has been limited by patient delay in seeking care. We sought to characterize prehospital delay in patients hospitalized for evaluation of heart attack symptoms. Methods and Results The Rapid Early Action for Coronary Treatment (REACT) is a multicenter, randomized community trial designed to reduce patient delay. At baseline, data were abstracted from the medical records of 3783 patients hospitalized for evaluation of heart attack symptoms in 20 communities. The median prehospital delay was 2.0 hours; 25% of patients delayed longer than 5.2 hours. In a multivariable analysis, delay time was longer among non-Hispanic blacks than among non-Hispanic whites, longer at older ages, longer among Medicaid-only recipients and shorter among Medicare recipients than among privately insured patients, and shorter among patients who used an ambulance. Conclusions The observed pattern of differences is consistent with the contention that demographic, cultural, and/or socioeconomic barriers exist that impede rapid care seeking. (Am Heart J 1999;138:1046-57.)