Introduction Giant sacral tumors often require a radical and extensive surgical approach. En bloc–sacrectomy implies a surgical challenge for the anatomical stability of the spino-pelvic joint. Different fusion approaches have been used to address this situation. We describe the surgical technique and summarize the clinical outcome after a total resection of giant sacral tumors and a transpedicular lumbo-iliac fusion. Material and Methods Case report of three patients who underwent an En-bloc sacrectomy between february of 2013 and February 2015. A combined extraperitoneal and posterior approach was used headed by a multidisciplinary surgical group of neurosurgeons, colorectal and plastic surgeons.We used a transperitoneal approach for anterior and lateral tumor isolation and for sacral dissection from ligaments and muscle insertion sites. Subsequently a posterior approach was used through which an L5-S1 diskectomy was performed followed by lateral osteotomies for sacral wing separation and bilateral S1 pedicle and laminae osteotomies with intact preservation of S1 nerve roots. Then the dural sac was ligated and the sacrum was amputated. For reconstruction of tumor site, a lumbo-iliac arthodesis was performed using polyaxial bilateral pedicle screws in L3, L4, L5 and two bilateral Transiliac Monoaxial screws. Vertical rods placed alongside the spine bylaterally maintaining lorditic axis, Cross links to connect the two vertical rods and Heterologous bone grafts were used. Results The three patients underwent a successful en bloc sacrectomy and lumbo-Iliac reconstruction without perioperative mortality and significant morbidity. Total tumor resection was performed in the three patients. None of the patients had gait disturbances after surgery. Patients were followed 6 to 30 months after surgery and at the final checkup there were no local recurrence reported and no instrumentation failure were noted. Conclusion Lumbo-iliac reconstruction through screw assisted transpedicular L3, L4, L5 and transiliac stabilization system after total oncologic sacrectomy provided spino-pelvic stability maintaining functional gait.