An elderly man with rheumatic valvular heart disease and atrial fibrillation presented with acute myocardial infarction. A coronary angiogram revealed complete occlusion of the right coronary artery (RCA), and we therefore considered that a thrombus might have obstructed the ostium of the RCA. We used a guiding catheter and the syringe of an aspiration device to remove two large dark red thrombi. A subsequent angiogram revealed that blood flow through the RCA had recovered, and the endomembrane of the RCA was smooth, with no evidence of stenosis or residual thrombus. In this case, thrombus aspiration via a guiding catheter was efficacious for treating this type of coronary embolism.