The exponential increase in the number of lung transplants being done 1 has not been accompanied by a corresponding increase in the number of donors. Currently still only about 15% to 20% of multiple organ donors have lungs suitable for transplantation. 2 This donor shortage remains the main limitation to more widespread use of lung transplantation. The scarcity of suitable donor lungs arose in part from rigid application of strict donor criteria. 3, 4, 5 These criteria have evolved somewhat with experience. However, the ever-increasing number of recipients has compelled us to consider the use of "marginal" donor lungs (i.e., donor lungs that fail to meet one or more of the previous rigorous criteria). We report here our satisfactory results with the use of marginal donor lungs during a 2 1/2-year period and present guidelines that have evolved regarding this approach as a means of addressing the donor shortage.