Oxygen-challenge test is an essential screening test for lung transplantation. The test is applied to brain dead patients and further evaluation of the patients for appropriateness of their lungs for organ harvest depends on having an acceptable result. The aim of the current study is to evaluate the status of the oxygen-challenge test in a group of brain death patients in Iran. We used the brain death database of the Organ Procurement Unit of Shaheed Beheshti University of Medical Science. Information about patients with brain death from X hospitals is registered in this database. Based on international criteria, an oxygen-challenge test result of more than 400 mm Hg is ideal, 300-399 is good and 200-299 is borderline for lung transplantation. A result of less than 200 is not suitable for lung donation. We used described the result of Oxygen challenge test. The mean oxygen-challenge test result was 266.6 ± 85.6 mmHg (range: 110 to 460). Regarding the specified cut-points; 6.7% of cases were ideal, 26.7% were good and 40% were borderline. Test result in 26.7% of the patients was not acceptable. In our study, more than 66% of brain dead patients have unacceptable or borderline results and only a small group of patients had ideal results for lung transplantation.