Transbronchial needle aspiration (TBNA) is a safe procedure with a reported complication rate of less than 1%. Pneumomediastinum after TBNA has not been reported in the English literature in the past. We present the case of a 65-year-old woman with widely metastatic small cell carcinoma, who developed pneumomediastinum after flexible bronchoscopy with TBNA. A persistent visible defect in the bronchial wall at the site of the needle insertion strongly implicated the TBNA as the cause of the pneumomediastinum.