Analysis of roentgenographic studies in 101 individuals with achondroplasia ranging in age from newborn to old age reveals little variability in the roentgenographic manifestations of this condition. The diagnostic findings at the different ages are outlined.Achondroplasia is a hereditary condition with an autosomal dominant mode of transmission.The practical importance of distinguishing achondroplasia from other forms of short limb dwarfism and several problems of clinical managment in which roentgenographic study is important are discussed.