Background: Surgical treatment of bone metastases has become increasingly important as patients live longer with metastatic cancer and one of the main aims is a long-lasting reconstruction which survives the patient. Conventional osteosynthesis may not be able to achieve this objective in the context of modern day cancer care. Methods: This study evaluates the oncological outcomes, treatment-related complications, and function after resection of metastases and reconstruction with modular tumor endoprostheses in 80 patients. All patients who underwent surgical treatment with modular tumor prostheses for bone metastases from 1993 to 2008 were traced by our tumor database and clinical information was recorded from patient case. Results: Mean age was 63 years. The most common primary tumors were renal cell (47%), breast (21%), and lung (8%). The proximal femur was affected in 45%, proximal humerus in 26%, and the distal femur in 17% of cases. In 22 cases, the tumor prosthesis was implanted during a revision operation. Mean overall survival after surgery was 2.9 years. Overall survival rate was 70% at one year and 20% at five years. Implant survival was 83% after one year and 74% at five years. Overall rate of operative revision was 18%. Conclusions: Our data collectively suggest that despite higher costs, implantation of modular tumor endoprostheses may be a suitable treatment for bone metastases with a low complication rate and rapid improvement in function in appropriately selected patients.