Nail guns are cheap and easy-to-access devices that are common in the industry and personal use and are widely used by untrained people. Life-threatening injuries may occur after a self-accident due to the use of these devices. We report the case of a 47-year-old man who had hemoptysis due to a lung parenchymal injury after nail gun use. Computed tomography revealed focal alveolar hemorrhage. Hemodynamically stable, the patient underwent surgery. Nail guns penetrating the chest can cause life-threatening situations. In the emergency department, rapid diagnosis and treatment is vital in preventing fatal outcome.