The number of patients awaiting lung transplantation (LT) and waiting time for surgery is increasing. In Australia, LT rates are 4. 6/million population/yr, which despite low organ donation rates, are the highest published in the world. The Australian organ allocation system allows identification of marginal donors and therapeutic manipulation where appropriate. This study aims to assess the impact of utilization of marginal donors and aggressive donor management. A comparison between published donor criteria and local practice is made, allowing assessment of the effect of using marginal donors on outcome. Donor management included antibiotic therapy, strict fluid management, physiotherapy, bronchoscopy and bronchial toilet, and alteration of ventilatory settings including initiation of pressure support. Blood gases were repeated to assess the results of interventions. Between January 1, 1995 and May 31, 1998, we performed 140 transplants from 112 of 219 (51%) lung donor offers. Of these donors, 48 (43%) satisfied all published criteria for suitable donor organs (Group 1 = ideal donors) and 64 (57%) did not (Group 2 = marginal donors). Criteria breached by the marginal donors were: an initial ratio of arterial oxygen pressure to fraction of inspired oxygen (PaO2/FIO2) < 300 mm Hg (n = 20), abnormal radiology (n = 39), pulmonary infection (n = 24), 20 pack-years smoking (n = 5) and age > 55 yr (n = 4). Therapeutic manipulation resulted in improvement in the PaO2/FIO2 ratio in 20 donors (Group 3) who would not otherwise have been used. Immediate and 24 h postoperative gas exchange and length of intensive care unit (ICU) stay was not different for recipients from donors from all three groups. Overall survival was 94% at 30 d, 83% at 1 yr, 70% at 2 yr, and 62% at 3 yr and was not significantly different from the three groups. We conclude that organ utilization can be maximized by therapeutic manipulation and utilization of marginal donors without compromising results from transplantation.