Intraprocedural stent thrombosis is a rare but serious complication of reperfusion therapy for acute coronary syndrome. There is currently no consensus on the intraprocedural management of intraprocedural stent thrombosis. It is difficult to attain thrombolysis in myocardial infarction flow grade 3, particularly in cases of cardiogenic shock. A 49-year-old man who presented with anterior ST-segment elevated acute myocardial infarction with cardiogenic shock underwent emergency percutaneous coronary intervention to diffuse proximal lesions in the left anterior descending artery under the support of intra-aortic balloon pumping. Intraprocedural stent thrombosis occurred following the postdilations with a 3.5- × 38-mm everolimus-eluting stent. Despite administration of argatroban and nitroprusside, and after frequent balloon inflations using 3.5-mm noncompliant balloons and thrombectomy, the no-reflow phenomenon was repetitively established. However, after brief and prolonged balloon inflations using 3.5- and 3-mm Ryusei perfusion balloon catheters (Kaneka Medix), the diffusely protruded thrombus inside the stent regressed, and thrombolysis in myocardial infarction flow grade 3 was obtained. The final intravascular ultrasound image showed a well-suppressed, in-stent thrombus and 24% gain of stent area (from 7.5 to 9.3 mm2). A Ryusei perfusion balloon enabled frequent, long inflation times without deteriorating hemodynamics during reperfusion in ST-segment elevated acute myocardial infarction complicated with cardiogenic shock. Thus, extended balloon inflation using a perfusion balloon is deemed a viable option not only for intraprocedural stent thrombosis but also for cases with a high burden of thrombi during the primary stenting procedure for patients with acute coronary syndrome.