Traumatic diaphragm injuries (TDI) are uncommon but can result in major morbidity or mortality if missed. Penetrating thoracoabdominal injuries carry a high risk of TDI, but can also pose a diagnostic dilemma due to their small size and the frequent lack of an associated hernia. Despite advances in imaging, diagnosis without presence of a hernia remains difficult and a high index of suspicion must be maintained. Chest x-ray remains an important tool in early diagnosis, but primarily relies on the presence of a hernia or a discontinuity of the diaphragm, which is not typically seen with penetrating injuries. Computed tomography has a higher sensitivity and specificity and improves preoperative diagnosis, but most TDI are still diagnosed intra-operatively. Minimally invasive modalities allow for both diagnosis and repair of suspected injuries in hemodynamically stable patients while avoiding the morbidity of an open approach. All penetrating diaphragmatic injuries require repair in order to avoid the major morbidity and mortality of a chronic diaphragmatic hernia. The principles of diaphragmatic injury repair are complete reduction of all abdominal contents, lavage and evacuation of any associated hemothorax or gastrointestinal spillage, and watertight, tension-free closure. Most injuries can be closed primarily, but some may require use of prosthetic material or other advanced reconstructive techniques for larger defects. Mortality remains primarily dependent on the mechanism of injury and the presence and severity of associated injuries, with overall Injury Severity Score serving as an independent predictor of early mortality.