Radiation-associated coronary atherosclerosis is a potential problem for patients who have had mediastinal irradiation for malignant tumors. This study identified 14 patients with radiation-associated coronary atherosclerosis, defines unique population characteristics, and analyses postsurgical problems and long-term outcome. Fourteen patients with radiation-associated coronary atherosclerosis and class III and IV New York Heart Association symptoms were identified because of mediastinal or chest wall irradiation (30 Gy) associated with anterior epicardial discoloration or fibrosis, aortitis with adventitial thickening, and inflammatory process over a proximal coronary artery. Two distinct treatment groups were analyzed. Coronary artery operation resulted in one hospital death, with vein grafts being used predominantly. The internal mammary artery could only be used in 3 patients because of vessel friability and mediastinal fibrosis. Postoperative right ventricular dysfunction and pulmonary problems were frequent. Severe pericardial inflammatory complications (fibrosis with graft closure, and constrictive pericarditis) present in 2 early patients resulted in routine anterior pericardiectomy after coronary artery operation without further problems. Long-term follow-up (100%) (range, 11 to 74 months) revealed that 1 patient died late and of the remainder (12 patients), 11 were in New York Heart Association class I and 1 in class II, experiencing three myocardial events. Thus, patients with radiation-associated coronary atherosclerosis have a low operative mortality but have risk of early right ventricular and pulmonary dysfunction. The routine use of internal mammary artery may not be possible and anterior pericardiectomy is recommended. Long-term results are excellent and no evidence of accelerated disease has been noted.