The incidence of hip instability in children with Down syndrome is 1% to 7%. The natural history is often progressive, with the typical onset of hypermobility of the hip evolving to habitual dislocation, persistent subluxation, and fixed dislocation, and eventually leading to the loss of independent mobility. Treatment focuses on stabilizing the hip joint and depends on the patient's age and the severity of the disease. Typically, surgical intervention is recommended for the treatment of patients with habitual dislocation, subluxation, and complete dislocation of the hip. When indicated, surgical management must take into account associated anatomic abnormalities of the femur and acetabulum. Hip instability in Down syndrome may persist despite surgical intervention and remains a difficult condition to manage.