The appearance of hip subluxation or dislocation in the cerebral palsy children is due to muscular and neurologic factors. In this paper the clinical and instrumental methods of early detection of hip joint instability were presented. Clinical measurements of spasticity around the hip joint should be applied to many times, but they do not provide to objective, reproducible data. The purpose of the paper was to present the etiological concepts of this spasticity complication. The methods is used in the author's clinical practice for establishing the dynamic status of investigated muscle groups. Pharmacological spasticity treatment and the operative methods are the useful methods of prevention of hip dislocation in children with cerebral palsy. For the totally dislocated hips the bony procedures should be advocated to make the reduction of dislocated hip joint. The clinical observations suggest that surgery of dislocated hip is very important factor improving the hip position, sitting balance and quality of life of the involved children.