The treatment strategy in 66 consecutive patients who underwent invasive therapy for acute myocardial infarction was analyzed, and specific attention was focused on the role of percutaneous transluminal coronary angioplasty. The following four treatment regimens were used: angioplasty alone (11 patients), angioplasty followed immediately by administration of streptokinase (15), streptokinase therapy alone (11), and streptokinase therapy followed by angioplasty (29). Reperfusion was achieved in 91%, 80%, 82%, and 72% of these subgroups, respectively. Angioplasty was particularly helpful in patients with severe residual stenoses after intracoronary administration of streptokinase and in patients in whom streptokinase therapy failed to reopen the occluded artery. Angioplasty further reduced the residual stenosis in 11 of 15 patients (73%) with successful thrombolysis, and it restored blood flow in 10 of 14 patients (71%) in whom thrombolysis had failed to do so. The incidence of reinfarction after therapy was similar in all four treatment groups. Patients in whom angioplasty was used either alone or in combination with streptokinase therapy had a significantly decreased incidence of subsequent revascularization (less than 30% compared with 82%). Angioplasty is of considerable value in patients undergoing invasive therapy for acute infarction. In some patients, it may be used as the only treatment; in others, it may be used to treat severe residual stenosis after initial streptokinase therapy. Finally, angioplasty achieves reperfusion in most patients in whom streptokinase therapy has failed.