Coronary artery stenosis with need for therapy is rarely seen in childhood. A 15-year-old girl with hypercholesterinaemia type II a was undergoing lipid aphereses therapy (once or twice a week) since she was 6 years old. The girl was seen in our hospital with stenocardia and depression of the ST-segment in the inferior ECG leads at rest. Myocardial scintigraphy with technetium 99 showed an ischemia of the infero-lateral left ventricular myocardium. During selective coronary angiography a 90% stenosis of the proximal right coronary artery over a distance of approximately 5 mm close to the ostium was found. Post stenotic dilatation of the vessel was obvious. In addition a diffuse 10% stenosis in the proximal and middle part of the right coronary artery was found. The left coronary artery appeared angiographically normal. After balloon dilatation, stent implantation was performed without complications with a 6 mm microstent. Reduction of the stenosis from 90% to 40% could be achieved. Ticlopidin 2 x 250 mg was started for thrombocyte aggregation inhibition. During the following 12 months the patient has been free of symptoms. Lipidaphareses has been continued as before. Stent implantation seems to be a successful treatment for coronary artery stenosis also in young patients.