Pneumomediastinum is a rare complication of a transbronchial lung biopsy. Common symptoms are chest pain, dyspnea, dysphagia, and specific electrocardiographic changes. We report a case of pneumomediastinum after a transbronchial lung biopsy. During the in-hospital stay, the symptoms and clinical picture rapidly improved without invasive treatment; therefore, the patient could be discharged after a few days. Approximately 1 month later, chest computed tomography was performed, which showed a complete resolution of the pneumomediastinum.