A pretransplant diagnosis was compared with the diagnosis made after macroscopic and microscopic examination of the explanted hearts in 112 cardiac transplant recipients. A coronary angiogram was recorded in 87.5% and endomyocardial biopsy was performed in 12.5% of patients within 1 year of the transplant. Echocardiograms were obtained in all patients. Before transplantation, 57.1% of patients were classified as having ischemic cardiomyopathy and 33.9% were classified as having idiopathic dilated cardiomyopathy (IDC). At explantation, severe coronary artery disease was found in all patients with a pretransplant diagnosis of ischemic cardiomyopathy, in 9 patients with a pretransplant diagnosis of IDC (6 of them had a "normal" pretransplant angiograms), and in 3 of the 4 patients with presumptive alcoholic cardiomyopathy. Left ventricular hypertrophy, undetected on echocardiography, was found at autopsy in 11 patients with presumed IDC, and acute myocarditis was found in 3 patients with a pretransplant diagnosis of IDC. A correct pretransplant diagnosis can lead to different management (e.g., bypass surgery rather than transplant), and may also portend different pre- and post-transplant prognoses. The results of this study suggest that an "in-depth" search for a cause should be conducted in all patients with heart failure, regardless of their clinical presentation. Our study also emphasizes the limitations of coronary angiography and echocardiography in patients with IDC and the need for improving current diagnostic techniques in these patients.