Radiographs of the hips of 69 patients with cerebral palsy were evaluated for the angle of Wiberg, acetabular angle, degree of subluxation, shape of the femoral head, and, when the appropriate studies had been performed, anteversion and neck-shaft angles. Abnormalities included various degrees of superior lateral subluxation or dislocation, dysplasia of the acetabulum associated with femoral head displacement, flattening of the medial and/or lateral portions of the femoral head, an increase in the anteversion angle, functional increase in the neck-shaft angle, and, in long-standing cases, secondary degenerative joint disease and pseudoarticulation. Neuromuscular imbalances and abnormal ambulation caused by cerebral palsy change the biomechanical forces on the hip and result in characteristic osseous changes. Recognition and proper treatment of these changes can significantly alter the clinical course of the disease.