The purpose of these experimental researches was to study the physiopathology of heart and lung preservation. The current problem of the paucity of lung and heart-lung donors can be solved either by retrieving the organs from cadavers or by increasing the time of preservation. Since the lung is more susceptible to ischemic injury if compared to the heart, we focused our studies on lung preservation techniques. Our results show that lung flushing prior to preservation is very important and the density and the potassium content of the solutions used for this purpose have to be chosen carefully. The addition of a surfactant precursor to the UW preservation solution maintained the pulmonary surfactant for at least 4 hrs of cold storage, but it failed to preserve lung ultrastructure for more than 4 hrs. The UW solution preserved heart ultrastructure for at least 6 hrs of cold-storage. Heat shock to induce the synthesis of heat shock proteins and catalse but failed to protect the heart from ischemia-reperfusion injury. The addition of vasoactive intestinal peptide (VIP) to the preservation solution maintained lung morphology and function upon 24 hrs of preservation and reperfusion and other authors showed that VIP protects the heart from ischemia-reperfusion injury. We are planning further investigations aiming to improve and extend the time of heart and lung preservation.