PTCA was performed in 28 patients with acute MI immediately after intracoronary streptokinase administration. Indications were failure to obtain reflow in 16 patients and high-grade residual stenosis in 12. PTCA was successful in 11 of 16 cases of streptokinase failure, increasing the overall reflow rate from 66% to 77%. PTCA reduced residual coronary stenosis by more than 20% in 9 of 12 cases in which streptokinase infusion was successful, with 1 acute reocclusion. The frequency of recurrent ischemic events in hospital was 76% in patients with a stenosis of 90% or greater after streptokinase infusion (no PTCA), 14% when residual stenosis was less than 90%, and 6% after successful PTCA. Late restenosis or reocclusion was documented in 5 of 11 PTCA cases (45%). Immediate PTCA after streptokinase administration produces increased clinical stability in hospital, but late restenosis is frequent.