Heparin-induced thrombocytopaenia is a life-threatening complication, affecting the morbidity and mortality of the patient if not properly treated. We report a case of a 75-year-old female patient who experienced enoxaparininduced thrombocytopaenia during medical treatment of acute ST-segment elevation myocardial infarction due to thrombotic total occlusion in the large right coronary artery.