Radiologic assessment of the cause of pulmonary parenchymal consolidation in end-stage heart failure may be difficult. From August 1982 to May 1989, 22 patients being considered for orthotopic cardiac allografts had parenchymal consolidation on their chest radiographs, most commonly in the right lower lobe. Our purpose was to determine from standard radiologic studies whether this consolidation represented alveolar pulmonary edema in an atypical basal distribution, pneumonia, or pulmonary infarction. This differentiation is important because pneumonia is an absolute and infarction is a relative contraindication to surgery, whereas successful transplantation can be performed in a setting of pulmonary edema. The chest radiographs were reviewed retrospectively. When available, pulmonary angiograms, nuclear medicine ventilation/perfusion scans, and needle biopsy findings were also evaluated. The radiologic assessment was correlated with the results of surgical, autopsy, or clinical outcome. None of the conventional modalities was very accurate--the plain chest film was correct in only 63%, nuclear medicine studies in 50%. Angiography was the single most useful test, with an accuracy of 75%.