We report an association between pericardial tamponade and early post-surgical occlusion of a coronary bypass graft. The presented patient developed pericarditis following myocardial infarction and bypass surgery. He was readmitted with myocardial reinfarction and cardiogenic shock 1 week after surgery. Coronary angiography revealed occlusion of a saphenous-vein graft to the right coronary artery. Concomitantly, pericardial tamponade was diagnosed on the basis of typical hemodynamics and echocardiographic findings. The patient recovered following pericardiocentesis and coronary angioplasty. We suggest a possible link between the 2 pathologies, whereby post-surgical pericarditis led to tamponade which decreased cardiac preload and resulted in systemic hypotension. Decreased coronary perfusion pressure and extrinsic compression by fluid in the pericardial space may have contributed to graft occlusion. Pericarditis and pericardial tamponade may therefore be risk factors for coronary bypass graft occlusion.