Despite major developments in the field of orthopaedic reconstruction of pelvic bone defects after pelvic tumour resection, massive pelvic bone loss with bone defect and pelvic discontinuity, still remains a complex problem. Resection of big musculoskeletal sarcomas of the pelvis and the later reconstruction of the residual defect constitutes one of the more exigent challenges of orthopaedic surgery. The authors present a method for reconstruction with a personalized prosthesis by mean of a rapid prototype specially designed for each occasion. The authors describe this individually prefabricated prosthesis based on rapid prototyíng technique with a computer-assisted design in a 3D printing based version. The results obtained are presented and commented.