1. A patient is described, the thirty-fourth reported, who shows all the skeletal changes of pycnodysostosis with the exception of the oral findings.

2. It is suggested that the pseudarthroses of the tibiae in our patient cannot be taken as evidence against normal union because of the possibility of inadequate management of the fractures.

3. We consider that the use of strong intramedullary nails in the treatment of long bone fractures in these cases is advisable.