Developmental dysplasia of the hip and idiopathic clubfoot are common musculoskeletal conditions in the pediatric orthopedic population. Although ultrasound or radiographic screening is generally recommended to rule out occult hip dysplasia, it has been suggested that children with clubfoot should no longer be screened. We report two cases of newborns with unilateral clubfoot and bilaterally stable hips that developed unilateral hip dysplasia on the same side as the foot deformity during clubfoot treatment. All cases previously reported in the literature are reviewed. We recommend systematic hip ultrasound screening in patients with idiopathic clubfoot. A second hip ultrasound or a pelvis radiograph, if the ossific nucleus has appeared, should be performed after completion of the clubfoot treatment if clinical examination is abnormal.