A 28-year-old man developed severe infundibular pulmonary stenosis (PS), coronary artery stenosis with sustained ventricular tachycardia (VT) 24 years after mediastinal irradiation (total amount of 40 Gray) for non-Hodgkin's lymphoma. Repair of right ventricular outflow tract and coronary artery bypass graft procedure were performed. Infundibular PS was successfully relieved after operation and VT was also controlled by medication. Mediastinal irradiation often causes various cardiac complications after a latent period. Therefore, continuous careful observation is mandatory in patients with the history of mediastinal irradiation.