Background/Aim. For almost two decades extremity amputation has not been the only viable option for patients with from bone cancer in the region of the hip and knee. Remarkable advances in implant technology, surgical reconstructive technique and adoption of new chemotherapy protocols provide a new option for surgeons who diagnose and treat bone tumors. Megaendoprosthesis has become widely accepted alternative in limb salvage surgery of the extremities. The aim of this study was to present an outcome of the treatment of bone tumors in the knee and hip region by the use of custom made megaendoprothesis. Methods. In the period 2006-2008 we adopted new clinical practice protocols for preoperative management in candidates for tumor megaprostheses of the hip and knee including: surgical tumor staging, histopathological verification, determinants of anatomical-mechanical defect, status of soft tissues, CT evaluation of the referent measures of pelvis, femur and tibia necessary for creation of custom made endoprosthesis and surgery plan, as well as modern, less invasive surgical approach. The patients were monitored during ≥ 24 months after the surgery for detecting possible complications. Results. All procedures were performed without complications during and immediately after the surgery. During the follow-up period not less than 24 months we failed to record any significant complications. Conclusion. Custom made megaendoprosthesis are the method of choice in the treatment of bone tumors in the region of the hip and knee at the Orthopedics and Traumatology Clinic, Military Medical Academy, Belgrade. The greatest challenge - ensuring longevity of a prosthesis can be achieved not only by prevention of common complications of arthroplasty procedures but, certainly, with the introduction of new methods for preoperative planning - computer-assisted technique of measuring referent sizes and software solutions for the selection and design of custom-made components of an endoprosthesis.