We report perforation of a side branch of left main coronary artery during coronary angiography. We suppose that the engaging of the catheter into a small side branch caused this complication. Furthermore, we observed that the conservative approach might be successful in the restoration of such coronary artery perforations. To the best of our knowledge this is the first reported case of left main side branch coronary artery perforation during angiography. (C) 2007 Elsevier Ireland Ltd. All rights reserved.