We analysed 17 patients with primary malignant bone tumour of the femur who underwent limb salvage surgery with the total femoral custom mega prosthesis during the period 1994-2008. The patients were in the age group of 12-73 years, with a mean age of 30.94 years. There were 14 males. The most common diagnosis was osteosarcoma. The average follow-up period was 54.05 months with the longest being 168 months. The average Musculoskeletal Tumour Society (MSTS) functional score was 66.6%. The two- to 14-year overall survival was 82.4%. Three patients died of disease and one patient required amputation. Complications encountered were deep infection and dislocation of the prosthesis.