Purpose Few studies have described mobilization approaches in developmental dysplasia of the hip (DDH). The present study describes the hip mobilization of a preterm infant (born at 33 6/7 weeks of gestational age) diagnosed with DDH. Design and Methods During the 43-day hospital stay, the infant was seen twice a week (ten sessions, 20 minutes each). All sessions included hip approximation maneuvers, with the hip positioned in abduction, lateral rotation and flexion, and lower limbs passive mobilization, which were taught to the mother. Early intervention with auditory, tactile, visual, and vestibular stimulations was also performed. The infant was assessed with hip ultrasound before and after treatment. Results At 34 2/7 weeks of gestational age, she was classified as Graf IIa (left: alpha: 55°, beta: 68°; right: alpha: 59°, beta: 64°). At 40 5/7 weeks, she was classified as Graf I for left (alpha: 67°; beta: 42°) and right (alpha: 66°; beta: 42°) hips. Practical Implications The intervention seemed to accelerate the acquisition of stability of dysplasic hips in a preterm infant. The outcome supports further investigation of hip approximation maneuvers as part of early stimulation in preterm infants with DDH during hospital stay.