The purpose of this study is to compare the results with hips graded by Graf classification using ultrasonography (US) in order to assess the diagnostic efficacy of radiography for developmental dysplasia of the hip (DDH) in infants younger than six months. Radiography may offer more comprehensive insights for screening programs and improve diagnostic precision, even if US is the standard for screening and diagnosing DDH in this age range. 100 hips from 497 newborns and babies under six months old who had hip US and radiography for DDH screening between August 2020 and September 2021 were included in this retrospective study. To find DDH indications, radiographs were reevaluated by a skilled pediatric orthopedic surgeon. The Graf classification was used to classify hips, and the main result was the accuracy of the diagnosis. Of the 100 hips examined, 71 (or 14.3%) of the right and 51 (10.3%) of the left hips displayed DDH radiograph indications. Radiographs of 43 (8.7%) right and 47 (9.5%) left hips revealed Graf grades IIa to IV, which allowed for a correct diagnosis of right- and left-sided DDH with specificity values of 87.0% and 92.4%, respectively. The radiographs of 7 (1.4%) right and 14 (2.8%) left hips showed Graf grades IIb to IV, which, when combined, allowed for the specificity of 86.1% and 91.1%, respectively, in the diagnosis of right- and left sided DDH. The findings of our study suggest that radiography may not be able to diagnose DDH in newborns and babies during the first six months of