SUMMARYThe author has reviewed the various types of diaphragmatic herniae which may present as a finding in the chest radiograph. Examples have been given to illustrate the appearance obtained in the various types of diaphragmatic herniation. A classification has been attempted, and the literature has been reviewed. The fact that these lesions may be symptomless has been emphasised, and attention has been drawn to the role of previous trauma in producing herniae at a later date.