Our primary study aim was to examine extent of, and factors associated with, delay in seeking medical care in a large multinational registry of patients with acute myocardial infarction (AMI) and unstable angina pectoris. A secondary goal was to examine the relation between duration of prehospital delay and receipt and timing of coronary reperfusion strategies. Investigators from 14 countries are participating in the Global Registry of Acute Coronary Events (GRACE) project. The study sample consisted of 3,693 patients with ST-segment elevation AMI, 2,935 with non-ST-segment elevation AMI, and 3,954 patients with unstable angina hospitalized between 1999 and 2001. The average and median delay times were longest in patients with non-ST-segment elevation AMI (6.1 and 3.0 hours, respectively) followed by patients with unstable angina (5.6 and 3.0 hours) and those with ST-segment elevation AMI (4.7 and 2.3 hours). Approximately 41% of patients with ST-segment elevation AMI presented to the 94 study hospitals within 2 hours of the onset of acute coronary symptoms; this compared with approximately one third of patients with non-ST-segment elevation AMI and unstable angina. Several demographic and clinical characteristics were associated with prehospital delay. In patients with ST-segment elevation AMI, duration of prehospital delay was inversely related to the receipt of thrombolytic therapy, but was inconsistently related to the use of percutaneous coronary interventions. The results of this study demonstrate that a large proportion of patients continue to exhibit prolonged delay in seeking medical care after the onset of acute coronary symptoms and remain in need of targeted educational efforts to reduce extent of delay.