Parallel to the increased acceptance of intervention for acute myocardial infarction, there has been a decrease in financial resources and reimbursement. To ascertain the relative cost to benefit of intervention, we evaluated 78 matched pairs of acute myocardial infarction patients from a prospective data base of 507 consecutive patients presenting with infarction from May 1986 to July 1987. The pairs were matched for age (mean 61 years), sex (68% male), and infarct location (43% anterior). Intervention (thrombolytics and/or percutaneous transluminal coronary angioplasty [PTCA]) was only applied to patients at less than 6 hours from symptom onset. Nonintervention patients were subsequently considered for angiography and revascularization (PTCA, coronary artery bypass grafting [CABG]) based on clinical criteria. Clinical outcome was evaluated by in-hospital mortality and uncomplicated status (free of angina, heart failure, or arrhythmias) at 72 hours. Intervention was associated with decreased mortality (5.3% versus 13%, p = 0.16) and increased uncomplicated course (43% versus 19%, p less than 0.001) as compared with patients not receiving intervention. Hospital procedures for the intervention and nonintervention group were as follows: diagnostic cardiac catheterization (99% versus 51%); PTCA (60% versus 0%); and CABG (14% versus 19%), respectively. The mean cumulative hospital and professional charges were $31,684 for the intervention group and $29,022 for the nonintervention group (p = 0.50). In conclusion, despite the potential marked incremental expense of technology associated with intervention for acute myocardial infarction, this analysis demonstrates that benefit in clinical outcome can be derived without substantially increased costs.