Although hip ultrasonography is gaining acceptance as the most effective method for the early diagnosis of developmental dysplasia of the hip, there is still some controversy regarding the use of ultrasonography as a screening method. The purpose of this study was to investigate prospectively the capacity of clinical examination findings and associated risk factors to detect developmental dysplasia of the hip defined ultrasonographically in infants. A total of 3,541 infants underwent clinical examination and hip ultrasonography. Measured against ultrasonography as a standard, the sensitivity and specificity of clinical examination were 97% and 13.68%, respectively. Graf type IIb or more severe developmental dysplasia was found in 167 infants (208 hips), at an overall frequency of 4.71%. Graf type IIa physiological immaturity was encountered in 838 hips, and of these, 15 hips (1.78%) developed Graf type IIb dysplasia and underwent treatment. Patient characteristics that were found to be significant risk factors were swaddling use, female gender, breech delivery and positive family history. Given its low specificity, our findings suggest that clinical examination does not reliably detect ultrasonographically defined developmental dysplasia of the hip in infants being screened for this disease.