[en] Left-sided homologous lung transplantations (LTP) were carried out in 18 mongrel dogs. Exhalation and perfusion scintigraphies was performed for interpreting the ventilation and perfusion in the postoperative course. The per cent ¹³³Xe storage and the exhalation per minute showed the significant reduction of the ventilation in the transplants dependent on the duration of the postoperative interval. The compensation behavior of the ventilation of the non-operated lung showed the compartment analysis. The perfusion index Q/sub L//Q/sub R/ with /sup 99m/Tc decreased progressively in the postoperative course. These investigation methods are slightly invasive. They allow the synoptic recording of the relationships between ventilation and perfusion. A differential diagnosis of complications after lung transplantations is not possible, however. (author)