Coronary Sinus Reducer (Neovasc, Inc., Richmond B.C., Canada) has shown to be an effective and safe treatment option for the treatment of refractory angina. Until now, a few number of complications related to its implantation have been reported. Coronary sinus perforation is a rare complication, more often related to cardiac surgery procedures. We report the first case of coronary sinus perforation after a sinus Reducer implantation.