The study tested the prevalence of graft vessel disease (GVD) in 54 paediatric heart transplant (HTx) patients (32 male, age 0-17 years) who underwent coronary angiographic investigations (N=117). These were evaluated according to the Stanford classification and additional criteria (peripheral obliterations, diameter fluctuations, pathologic tapering) were applied for risk assessment (no GVD/minimal lesions, GVD without Stanford lesions, accelerated GVD). In H&E stainings from right ventricular endomyocardial biopsies (EMB=169) diagnosis of acute cellular rejection (ACR, ISHLT) and microvasculopathy were performed. Mild rejection was found in 43% (N=44) and severe rejection in 7% (N=7) of EMB early (1st year) and mild rejection in 31% (N=32) and severe in 8% (N=9) late (>3 years) after HTx. Microvasculopathy was present in 22% of EMB. Risk assessment of coronary angiographies showed no GVD/minimal disease in 25% (N=29), GVD without Stanford lesions in 12% (N=14) and different grades of accelerated GVD in 74% (N=74) of studies. All patients dying due to cardiac related causes of death (N=6, 3-12 years after HTx) had evidence of GVD. The data show GVD to be an important cause of late cardiac related deaths in this population.