Nail-gun injury is commonly encountered in the emergency department. The severity of the injury depends on the specific injuries to organs and vascular structures. Computed tomography (CT) is the ideal imaging test of choice, as it can identify the more critical injuries that require immediate intervention. We present a case of self-inflicted nail-gun injury with intracranial and intracardiac nails that was optimally evaluated with CT. CT significantly changed the patient's management, giving priority to potentially life-threatening penetrating cardiac injuries.