Severe illnesses make a patient prone to depression and depression adds to the burden of the disease. Patients awaiting lung transplantation have severe disease and most of them know that they may not be lucky enough to breathe through a new lung. Such expectation along with restrictions that the illness imposes makes them prone to depression. In the current study we investigate the presence of depression in a group of patients on lung-transplantation waiting list in Iran. In a cross-sectional study from August to September 2007, 64 lung-transplantation candidates from lung transplantation clinic of Masih Daneshvari Hospital have entered the study. The participants signed a written consent for participating in study. We used the Beck questionnaire to evaluate patients’ depression. It is a highly validated questionnaire to identify the presence and severity of depression. It has 21 items and higher scores indicate more severe depressive symptoms. The total score of questionnaire ranges from 0 to 63. In Iranian population, scores from 0 to 15 indicates no problem, 16 to 30 indicate mild, 31 to 46 moderate and 47 to 63 indicate severe depression. The mean age of the patients was 36.6 ± 13.6 years. 70.3% of the patients were male and 29.7% were female. Regarding the marriage status, 40.6% were single and 59.4% were married. In the studied patients, 43.8% had no depressive symptoms, 37.5% had mild depression and 18.7% had moderate depression. We found that more than half of the patients on lung transplantation waiting list have some degrees of depression. Since there is a risk of non-compliance to treatment and follow-up protocols in depressed patients, we recommend depression screening before transplantation and if diagnosed, closer observations of the patients regarding the mental morbidities like depression.