Pneumatic nail guns are hand-held tools used in industrial and construction settings. Nail guns cause the most trauma with hospitalization among construction workers. To our knowledge, we report for the first time a case of pneumomediastinum from a nail gun injury to the hand. Our patient was a 40-year-old male construction worker who shot a nail gun into his hand. He became acutely dyspneic and was found to have a pneumomediastinum due to air insufflation. He later underwent tube thoracostomy and intubation. To our knowledge, this is the first report of pneumomediastinum from a nail gun injury to the hand.