We experienced 2 cases of surgical treatment for left atrial myxoma combined with coronary artery bypass grafting (CABG) using only in situ arterial grafts. A 58-year-old man who had undergone CABG [left internal thoracic artery (LITA)-right coronary artery (RCA) and saphenous vein graft (SVG)-left anterior descending artery (LAD)] 14 years before was admitted to our hospital, complaining of anterior chest pain. Coronary arteriography demonstrated total occlusion of the LAD and RCA, as well as the stenosis of high lateral branch (HL) and SVG. Left atrial myxoma was incidentally detected by echocardiography. Myxoma was resected at first, and then the right internal thoracic artery (RITA) was anastomosed to the LAD. The postoperative course was uneventful. A 69-year-old woman was admitted to another hospital, complaining of chest pain and dyspnea. Coronary arteriography revealed stenosis of LAD, left circumflex artery (LCx) and HL, as well as left main trunk (LMT). Left atrial myxoma was incidentally detected by echocardiography. Myxoma was resected at first, and then CABG [LITA-HL, gastroepiploic artery (GEA)-RCA and RITA-LAD] was carried out. The postoperative course was uneventful. The priority between CABG and the surgical treatment for cardiac myxoma remains controversial from the point of view of myocardial protection and prevention of systemic embolism of myxomal fragment.