Heparin-induced thrombocytopenia type II (HIT type II) is the most serious complication of heparin treatment apart from bleeding, which is the most common side effect. Eleven days after coronary bypass grafting, a 71 year old patient showed a posterolateral myocardial infarction and a thrombocytopenia of 80,000/microliter. This was considered a postoperative thrombocytopenia. Coronary angiography revealed closed venous bypass grafts. The right coronary artery (RCA) was revascularized by percutaneous transluminal coronary angioplasty (PTCA) and stent placement. During both coronary angiography and PTCA, heparin was administered to the patient. The platelet number did not change. Four days later the patient showed an inferior myocardial infarction and an AV-block III degrees and a syncope. The following coronary angiography revealed RCA stent occlusion. HIT type II was presumed and recanalization was carried out using Lepirudin (Refludan) as the anticoagulant. After placing the guide wire, thrombi could be seen in the proximal RCA. Abciximab (Reo pro), a monoclonal antibody against the glycoprotein IIb/IIIa receptor was additionally administered. Coronary angiography on the next day revealed only a small remaining thrombus. The AV-block disappeared immediately after revascularization. The diagnosis of HIT type II was confirmed through heparin-induced-platelet-activation-test (Hipa-test) and immunoassay (PF 4/heparin-ELISA). This case report illustrates the complicated diagnosis of HIT type II and the successful simultaneous use of Lepirudin (Refludan) and Abciximab (Reo pro). The number of platelets should be checked daily during heparin treatment. In the case of a thrombocytopenia, the treatment should be stopped immediately, and Hipa-test and PF 4/heparin-ELISA should be carried out.