A drug-eluting stent was implanted in four patients, a man aged 67 and a woman aged 42 with acute myocardial infarction, a woman aged 41 with unstable angina pectoris and a man aged 41 with stable angina pectoris. All suffered stent thrombosis after discontinuation (in three cases prematurely) of clopidogrel therapy. Reasons for discontinuation included allergic reaction, a dental procedure and refusal of reimbursement by the insurer. In order to restore stent patency they were treated by percutaneous coronary intervention and all patients suffered irreversible myocardial damage. Combination therapy using acetylsalicylic acid and clopidogrel during and after angioplasty for the prevention of long- and short-term complications is necessary. Stent thrombosis after drug-eluting stent implantation usually occurs within 1-4 weeks following discontinuation ofantiplatelet medication. These cases stress the importance of antiplatelet therapy after stent implantation. Physicians, dentists and patients must be aware of the risk of the early discontinuation ofantiplatelet therapy.