Purpose: The gold standard treatment for primary bone sarcoma is limb saving (salvage) procedure in the indicated case. Today, limb saving surgery is considered safe and routine for approximately 90 % of patients with malignant bone tumours involving extremity. In our retrospective study of 40 patients having malignant bone tumour treated by limb salvage and mega prosthesis replacement of different regions like proximal humerus, proximal femur, distal femur, proximal tibia, we have studied mid and long term follow-ups in terms of life expectancy (survival), recurrence, implant-related complications, and functional outcome. Methods: Retrospective study of 40 patients treated by limb salvage surgery using mega prosthesis during the study period (2014 to 2020). All patients were confirmed by biopsy. Neo-adjuvant chemotherapy was given as per the case. Results were analyzed at follow-up ranging from 2 years to 6 years with a mean of 3.2 years. Results: 15 out of 40 (37.5%) were more than 5 years and 28 out of 40 (70%) were more than 3 years of follow-ups. Osteosarcoma was the commonest tumour (55%). There were no implant-related complications. 37 out of 40 (92.5%) patients with mega prosthesis were found to be tumour-free and without any complications on the last follow up. Conclusion: Limb salvage surgery for malignant bone tumours by mega prosthesis is a good treatment in selected cases. It gives good tumour control and good functional life.