The skeletal dysplasias represent a diverse and complex group of conditions related to abnormal bone growth and development. The aim of the chapter is to present a framework and approach to diagnosis. In the information section, the major skeletal dysplasias are reviewed and presented in summary tabular form. The prenatal sonographic features, molecular and genetic considerations and comments as to potential outcome are reviewed. In the imaging considerations and images section, an initial approach towards diagnosis is presented in a decision tree format followed by a table of potentially differentiating findings. Finally, images in tabular form are presented for a number of specific conditions.