The optimum method for lung preservation in preparation for transplantation remains unresolved. In this study we evaluated the effectiveness of Pentoxifylline to find an ideal perfusate to increase the success of preservation in a model which consisted of exposing the left lung of each experimental dog to normothermic ischemia after clamping the pulmonary artery, vein and bronchus. After ischemic periods of three hours, pulmonary circulation were reestablished. The left lung of dogs was perfused with Euro-Collins solution alone in group A (n=2) and with Euro-Collins solution containing 2500 ng/ml Pentoxifylline in group B (n=2). The mean ischemic time was three hours in both groups. Specimens for light and electronmicroscopic investigations taken seven days after the initial operation, showed that addition of Pentoxifylline to the perfusate appears to be beneficial in the preservation of allograft patency in organ protection.