Background and Aim: Efficient manpower is the most important of military capital, and many studies have shown the relationship between personal health and organizational performance. The preparation of military cadet volunteers to enter aeronautical training and the provision of optimal services in the form of well-trained pilots requires many material spiritual resources that disabilities, make them waste. Methods: This is a descriptive, cross-sectional, retrospective study with target population of Iranian air force cadets with early and permanent medical disqualification from 1986 to 2016. Results: 80 cases were detected, including 25 kills and 55 early and permanent medical disqualification. The main causes were ear, nose and throat, psychiatry and cardiac, respectively. Common diseases include motion sickness, generalized anxiety disorder, adjustment disorder and epilepsy, respectively. The total number of lost service years was 1412 person years and the average of lost service years was 25.67 person years. Most of the lost service years were related to medical causes included ear, nose and throat, psychiatric and cardiac, and diseases included motion sickness, generalized anxiety disorder and adjustment disorder, respectively. Neurologic causes resulted in highest average of lost service years and high blood pressure was the major diseases, respectively. Conclusions: Due to the lack of similar studies, the results of this study were compared with the data, which extracted from previous studies in the pilot’s population. Because of occupational similarity between pilots and cadets, It was expected that the most common causes in pilots and cadets should be the same, but we found that the results are very different.