This article addresses two important questions: What is the relationship between limited abduction and hip dysplasia in infants? Does untreated limited abduction in the infant ultimately lead to developmental dysplasia of the hip? In the authors' population of 683 babies, limitation of abduction had a sensitivity for the diagnosis of hip dysplasia of 69%, a specificity of 54%, a positive predictive value of 43%, and a negative predictive value of 78%. In the group with sonographically proven hip dysplasia, 70 of 226 babies (31%) showed no limitation of abduction, and in the group without dysplasia 210 of 457 (46%) showed manifest limitation of abduction. One hundred thirty-six babies with limited abduction but a normal sonographic examination were left untreated. They were re-examined at an average age of 5+3 years (range 2+0-9+5). All had developed normally, both clinically and radiographically.