We developed a new solution, ET-Kyoto (ET-K) solution, and compared its efficacy in 20 h lung preservation with that of Euro-Collins (EC) solution in a canine left lung transplantation model. The lungs were flushed with ET-K solution (ET-K group, n = 5), with EC solution plus prostaglandin E1 (PGE1) pretreatment (EC + PGE1 group, n = 6) or with EC solution (EC group, n = 6), and were stored at 4 degrees C for 20 h. The function of left lung grafts was assessed 40, 70, and 130 min after transplantation. The arterial pressure of oxygen (PaO2) in the ET-K group was significantly greater than in the EC + PGE1 group (p < 0.05 or p < 0.01) and in the EC group (p < 0.01). The peak inspiratory pressure and wet to dry weight ratio in the ET-K group were significantly lower than in the EC + PGE1 group and in the EC group (p < 0.05 or p < 0.01). Pulmonary vascular resistance in the ET-K group 130 min after reperfusion was significantly lower than in the EC group (p < 0.05). All the transplanted lungs in the EC + PGE1 group and the EC group showed histological evidence of pulmonary edema, whereas all in the ET-K group showed no signs of edema. We concluded that ET-K solution is superior to EC solution with or without PGE1 pretreatment in 20 h canine lung preservation.