A distinction is made between acute injury to the diaphragm (18 cases) and late sequels of such lesions (enterothorax, 9 cases). The acute trauma is often not felt as such and it is only after some time that its consequences manifest themselves. The effect of a trauma on the diaphragm depends on whether the former acts on the abdomen or thorax. Surgical repair of the damaged diaphragm is nearly always feasible regardless of whether the operation is performed at an early or late stage of the injury. In only two cases (since 1963) was it necessary to resort to heteroplastic material, viz.: lyophilized dura mater. The possibility that viscera displaced into the thorax are also injured must be taken into consideration. Rupture of the diaphragm involved the left side in 95% and the right half in 5% of the cases (protection provided by the liver).