- BACKGROUND: Subcutaneous emphysema can result from rupture of the respiratory or gastrointestinal systems, commonly occurring after trauma or surgery, as well as from rupture of alveoli as pneumothorax or pneumomediastinum. Spontaneous pneumomediastinum with subcutaneous emphysema is rare in children without chest or neck trauma. Here, we report 2 cases of spontaneous pneumomediastinum with exercise-induced bronchoconstriction. CASE REPORT: The first case is an 11-year-old boy who presented with neck pain after vigorous exercise. Radiography showed pneumomediastinum. The second case is a 15-year-old boy who presented with pleuritic chest pain and respiratory failure requiring intubation. We extensively investigated the possible causes of pneumomediastinum. Both patients had no history of trauma or asthma, and were diagnosed with exercise-induced bronchoconstriction. They were discharged after conservative treatment, without complication. CONCLUSIONS: Early recognition and investigation of serious conditions should be promptly done in spontaneous pneumomediastinum patients. Conservative treatment, extensive investigations of predisposing factors, and treatment are important.