We present a 44-year-old female patient with anterior myocardial infarction caused by embolization from mitral valve prosthesis due to inadequate anticoagulation. The patient underwent a cardiac catheterization within the 1st hour of arrival. The angiography showed total occlusion of the left anterior descending coronary artery after the second diagonal branch. Percutaneous transluminal coronary angioplasty and stenting were performed, and coronary artery perfusion was restored. The pain disappeared completely immediately after this intervention. Transthoracic echocardiography shortly after this intervention showed normal prosthetic valve function and no thrombus. Transesophageal echocardiography performed 2 days later revealed no thrombus at the prosthetic valve. In conclusion, this case demonstrated that coronary embolism may occur even without prosthetic valve thrombus or dysfunction with suboptimal International Normalized Ratio levels, and can be successfully treated with percutaneous transluminal coronary angioplasty and stenting.