Lower gingival squamous cell carcinoma (SCC) frequently invades the mandibular bone and buccal or lingual oral mucosa. In the concept of en bloc surgery of malignant tumors, it is advisable to prefer segmental mandibulectomy for T3-T4 lower gingival carcinoma that had radiologic bone involvement and resection of soft tissue on the buccal or lingual side with negative border of margin. Consequential defects of oral mucosa and mandible need immediate reconstruction to provide the maximum probability of cure and quality of life with minimal donor site morbidity. The aim of this study was to evaluate the fibula osteocutaneous flap with skin island as a means to meet both hard and soft tissue reconstructions needed in a one-stage procedure of gingival SCC. Data of 17 patients, with gingival SCC pathologically and who underwent en bloc operations including segmental mandibulectomy and reconstruction of mandible and intraoral mucosa with fibular flap, were retrospectively analyzed. The segmental mandibular defects ranged from 8 to 17 cm, and intraoral soft tissue defects ranged from 4 degrees at 2.5 cm to 8.5 degrees at 4 cm. The flaps survived in all 17 patients including 9 patients who received postoperative radiotherapy with good final function of the lower leg. Of 17 patients, 11 had with no evidence of disease with a mean follow-up period of 25 months. Our study results, together with literature findings, revealed that the fibula that had a long length of good-quality bone and sufficient blood supply were suitable for stable osteosynthesis, with the overlying skin suitable in thickness and without limitation of skin flap size for intraoral reconstruction especially after ablative surgery. This method provides oral and maxillofacial surgeons with a means to meet both hard and soft tissue needs in a one-stage procedure for extensive resection of gingival SCC.