The incidence of atherosclerosis of the heart transplant in long term survivors is 38% at 5 years. In the present work, myocardial perfusion 201Tl-SPET was assessed as a non-invasive diagnostic method for the detection of postransplant coronary artery disease, as well as its efficiency with regard to other techniques. Twenty patients, aged (47 +/- 9) years old, who underwent heart transplantation at least 3 years earlier, were studied by 201Tl-SPET. Qualitative and quantitative analysis of the images were performed. It was found ischemia in 6 patients, 4 of them asymptomatics. In 5 of the 6 positive cases by SPET coronary stenosis was found by angiography. Kappa coefficient and percent of agreement were k = 0. 76 and Pe = 90%, respectively. There were no relationships among rejection crisis, sepsis by cytomegalovirus and coronary artery disease detected by using 201Tl-SPET (p > 0.05). The most relevant risk factors in the sample were hypertension and hyperlipidemia. Two patients died because of coronary artery disease. It was confirmed by necropsy findings. These results suggest that thallium-201 myocardial perfusion tomography could be useful to detect coronary artery disease in the transplanted heart.