The current study investigated the causality between the musculoskeletal injuries of the patients who visited our military hospital and their military-related activities. The surgeon diagnosed the patients and let them answer the questionnaire on pain and causes from April 1, 2008 to May 30, 2008. The included 287 male patients were mean 21 years old(mean height 175 cm and mean weight 69.4Kgf). The visiting time after injury was mean 53 days. The visual analog scale of pain was mean 5.1 points. The 30% of visiting patients answered the most common cause of injury was the military training. The Most common site of injury was the knee, in 38% of patients(111 of 287). Seventy two percent of patients suspected the causality between their injuries and military activities. In military activities, a special stretching program before training, especially for the knee, is required to reduce musculoskeletal injuries. And, the injured military people have to access the medical treat as soon as possible.