Inflammatory bowel diseases have been recognized as predisposing factors to atherosclerosis and thrombotic events, involving both the venous and the arterial circulatory systems. We report the case of a 70-year-old man who presented with ST elevation myocardial infarction during the active phase of ulcerative colitis (UC). Because of the ongoing hematochezia, after successful revascularization of the culprit vessel, the patient was medicated with Clopidogrel, in place of one of the more powerful new oral P2Y inhibitors that currently represent the gold standard therapy. Few days later a second elective percutaneous coronary intervention (PCI) on a non-culprit vessel ensued in a life-threatening early massive stent thrombosis involving the left main. During and after emergency PCI antiplatelet therapy was upgraded to Abciximab and Ticagrelor; this therapy proved successful in handling the massive stent thrombosis in the absence of severe bleeding complications. This case is unique and paradigmatic of the complex management of patients with coexisting active UC and acute coronary syndromes; it demonstrates as in this setting the balance between hemorrhagic and ischemic risk is labile and tricky to assess.