A left lung allotransplantation was performed on a 42-year-old man dying from hypertrophic emphysema, massive silicotic fibrosis, and tuberculosis with intractable cor pulmonale. His condition improved for the first five days, then the transplant became more and more difficult to ventilate. Lung scans performed on the last five days showed the transplant was better perfused than the remaining lung. This ventilation-perfusion imbalance resulted in anoxic heart arrest on the 11th day. Postmortem examination showed the transplant was compressed by the remaining lung. Although the edematous load was identical in both lungs, compliance of the transplant was only half that of the other. Desquamative pneumonitis, found in the transplant, could represent infection or rejection.