The psychosocial functioning of patients arriving at the emergency department with an acute myocardial infarction early enough to be candidates for treatment with thrombolytic agents was compared with that of those arriving later. Patients who arrived within 3 hours were significantly more anxious when assessed 1 week after admission and had a consistently worse pattern of psychosocial adjustment 3 months after hospital discharge than did those who arrived later. The implications of these findings for efforts to improve early arrival at the emergency department, as well as for medical and psychosocial outcomes after acute myocardial infarction, were considered.