The diaphragmatic surface of each lung is the most inferior surface that is concave in shape. It is bounded by the inferior border of the costal and mediastinal surfaces of the lung. It lies superior to the diaphragmatic dome on each side; indeed, the more elevated dome on the right side is associated with a more pronounced complimentary concavity on the inferior right lung surface than on the left side.
The posterolateral margin of the diaphragmatic surface is slightly more inferior and more acute in angle than the anterior margin. It projects into the costodiaphragmatic recess during inspiration.