The skeletal dysplasias or osteochondrodysplasias are a clinically and genetically heterogeneous group of disorders of bone and/or cartilage. They are characterized by abnormalities in pattering, linear growth, differentiation, and maintenance of the human skeleton. While they have been considered to be generalized disorders of endochondral and/or membranous ossification, the extent of their clinical and molecular heterogeneity is still being elucidated. In the 2006 revision of the International Nosology and Classification of Genetic Skeletal Disorders, 372 different conditions were listed in 37 groups defined by such molecular, biochemical, and/or radiographic criteria. The evaluation of patients with chondrodysplasias mandates a multidisciplinary approach involving clinical geneticists, radiologists, molecular biologists, and biochemical geneticists for diagnosis, and a host of surgical specialists for management of their many complications. Our International Skeletal Dysplasia Registry is a worldwide referral center for the skeletal dysplasias, and we have received cases from over 3000 physicians from 50 different countries and have been involved in the identification of the molecular defect in over 40 disorders involving over 25 different genes. Instructions on accessing the Registry, using the diagnostic services provided and contributing cases for collaborative research can be found at http://www.csmc.edu/skeletaldysplasia.