Hip arthroplasty is the complete replacement of the articular components of the cup and proximal part of the femur. The main objective of radiological imaging is to check the correct position of the prosthetic components in the post-operative phase and to highlight any complications in the subsequent phases. The best investigational technique for the post-operative study and follow-up of complete hip prosthesis is traditional radiology, which is able to visualize well the prosthetic components and their relationship with adjacent bone structures. In case the patient complains of a clinical-functional problem, the rehabilitator – through the radiological study – can trace the root cause, provided that the X-ray has been performed in the correct way.