A 42-year-old man presented at our attention with chest pain. His cardiac risk factors were smoking habit and family history of coronary artery disease. At the ECG, a mild ST-segment elevation in the inferior leads was shown. A normal left ventricular function was demonstrated at the echocardiography. An emergency coronary angiography was performed, and an extensive thrombosis of the right coronary artery and midleft anterior descending coronary artery was visualized. A primary angioplasty with thrombus aspiration and direct stenting of both sites followed. Biochemical analysis revealed a high plasma homocysteine level with a homozygotic anomaly of the 5,10-methylenetetrahydrofolate reductase. Currently, a nine-month followup negative for cardiac events is recorded.