A 3 7 -year-old man who had suff ered right chest pain while mowing weeds was transferred to our hospital. A chest roentgenogram revealed a needle-like foreign body overlying the cardiac silhouette and chest CT confi rmed an intracardiac foreign body. The patient underwent emergency operation,and a foreign body was removed under cardiopulmonary bypass and performed cardiac repair. A foreign body penetrated right lung and reached it in the left atrial cavity. The patient recovered uneventfully without any symptoms of infections.