This report describes an internal mammary artery by-pass grafting to the anterior descending coronary artery in a man with an unstable postinfarction angor pectoris and a "situs inversus totalis" condition. The association of "situs inversus totalis" and atherosclerotic coronary artery disease has the same incidence as in normal people. To the authors' knowledge, this is the second case in medical literature of coronary artery by-pass surgery with internal mammary artery graft in a patient with "situs inversus totalis".