Incidence of chest and/or abdomen trauma has increased over the last three decades; it tends nowadays to stabilize. Among severe trunk injuries, diaphragm rupture--a life-threatening condition--occurs in 7% of cases. Overall mortality is around one third of casualties. Young (average 40 years of age) men (80% of cases) are especially exposed. Biomechanics, epidemiology, anatomy, physiopathology are reviewed. Comments are given upon clinical suspicion of the rupture as well as establishing its diagnosis, upon associated injuries, surgical indication for repair and treatment, with a special notice for resuscitative precautions. Numerous typical examples are illustrated.