Background: The management of mandibular tumors in pediatrics represents a great challenge in both the oncological and the reconstructive aspects. The free fibula has been proven to be the workhorse for mandibular reconstruction in adults. However, it's growth potential, feasibility of dental rehabilitation and its impact on the entire craniofacial skeleton are not clear. Methods: We herein present our experience over 20 years from july 2002 to June 2025 at the National Cancer Institute, Cairo University, Cairo, Egypt using the free fibula flap in reconstruction of post ablative mandibular defects in pediatric patients. Long term assessment of the growth of fibular segments, facial symmetry and dental rehabilitation were analyzed. Results: A total of 26 pediatrics patients. The age ranged from 2 to 18 years with girls to boys ratio of 1 to 1.35. All patients had a preoperative tissue diagnosis and were assessed at the MDT preoperatively. Tumors included both odontogenic and non odontogenic. Sixteen patients received peri operative chemotherapy while 5 patients received post operatively. Six patients received preoperative XRT and another 8 patients received post operativeXRT. All flaps survived except for one patient that developed complete flap loss. This was salvaged with pectoralis myocutaneous flap. Another patient developed postoperative venous thrombosis and underwent successful re exploration. Post operative infection was reported in 10 patients. Bone segments showed different patterns of growth, while cephalometric studies demonstrated symmetrical facial skeleton. Conclusion: In pediatric population, free fibula for mandibular reconstruction achieves rapid rehabilitation with satisfactory long term functional and aesthetic outcomes.