The effect of genetic factors on hip dislocation, acetabular dysplasia, and developmental dysplasia of the hip (DDH) has long been recognized. In this report, we presented a large family that showed single gene inheritance for DDH. Pedigree analysis of a pregnant woman revealed a history of DDH in 16 members of the family. Although the pedigree showed autosomal dominant inheritance with reduced penetrance, the prevalence of DDH was considerably high, almost accounting for one-third of the family members, and skipping only one generation. Of 16 cases, three patients were diagnosed at our center. The remaining 13 patients were diagnosed at other centers. Dislocation was diagnosed very late in most of the family members, while four cases were diagnosed at birth. All family members were informed by a detailed clinical letter and recommended evaluation for DDH at every birth. © 2007 Türk Ortopedi ve Travmatoloji Derneǧi.