Spontaneous pneumomediastinum(SPM) is an uncommon disease that is defined as the nontraumatic presence of free air in the mediastinum without any apparent underlying disease. We report a case of recurrent spontaneous pneumomediastinum without any direct precipitating cause. A 21-year-old woman was admitted to hospital suffering from chest pain that occurred during walking(?). She had previously been well. She did not complain of cough or vomiting prior to this presentation. Upon admission, the physical examination and Electrocardiogram findings were normal. The chest x-ray and chest computed-tomography showed a pneumomediastinum. She was successfully managed conservatively. Twenty seven months later, she was readmitted with chest pain, which again occurred during the same activity. The recurrent SPM was confirmed by the chest x-ray and chest computed-tomography. She was managed in the same manner as before and made an uneventful recovery. This is the first case of recurrent SPM in Korea.