In this paper we present indications for usage of oncological prosthesis in the treatment of metastases in proximal femur. According to our experience, based on clinical material of 78 patients treated between year 1997 and 2007 in Spine Surgery, Onclological Orthopaedics and Taumatology Clinic, University of Medical Sciences in Poznan, the indications are: massive bone loss, second surgery in the same place, damage of articular surface, small possibility of stable union, threatening patological fracture. At the appropriately selected group of patients application of onclological prosthesis lets for restoring the function of the limb, reducing or bearing pain complaints or removing the entire methastasis.