We investigated the efficacy of four different preservation solutions in a heart-lung model in the rat. The heart and lungs of the donor were perfused under standardised conditions of temperature, pressure and flow. We studied 4 groups: group 1 received Stanford solution to heart and lung; group 2 received St. Thomas' solution to heart and Papworth solution to lung; group 3 received University of Wisconsin solution to heart and lung; and group 4 received University of Wisconsin solution to heart and Papworth solution to lung. Lung function assessed by arterial pO2 at a standardised FIO2 was significantly better in groups 2 and 4 than in other groups. However, cardiac function as assessed by cardiac output, stroke work index and minute work index was significantly better in group 4 than in any other group. Overall, the combination of solutions in group 4 provided the most effective preservation in this model.