We have developed a standardized technique for ultrasound guided intra-articular injection of the hip joint with the view to extending routine intra-articular injection of hyaluronans and steroids to the hip, as commonly used in the knee. Our experience has shown that in expert hands, US guidance for intra-articular injections is a technique that is simple to carry out, effective, safe and well tolerated. It can be repeated in the same patient without significant changes in the tolerability and safety and without risks of repeated exposure to radiation for the patient and the operator. The clinical and scientific data obtained with our technique demonstrate that ultrasound guided therapy of the hip can reduce symptoms and probably slow down structural osteoarthritic damage by decreasing inflammatory flares, furthermore it might reduce both the assistance costs and costs related to total hip replacement. This book describes the technique of ultrasound-guided injection of the hip, clinical reports and scientific results, and deals with the future prospects of intra-articular therapy. We hope that this book can be, as well as a complete treatise of the state of the art of ultrasound guided intra-articular injections of the hip, also an incentive for specialists who want to start performing this therapeutic technique.