The arthrogram plays an important role in the diagnosis and treatment of congenital dislocation of the hip (CDH), because congrous reduction has been related with hip outcome. We have reviewed 29 children younger than 1 year of age (34 hips) diagnosed and treated in our hospital for CDH, and we have recorded three radiologic parameters: acetabular index, acetabular floor thickness, and grade of dislocation. We also have evaluated three surgical and arthrogram findings (limbus, ligamentun teres, and transverse ligament) in order to study their statistical correlation, and consequently, to evaluate arthrogram usefulness. Results show a significantly high acetabular index and floor thickness as secondary to absence of femoral head.