Resection of advanced gingivo-buccal tumors results in a posterolateral mandibular and large soft tissue defect. Because of large soft tissue requirement, these defects are difficult to reconstruct using a single osteocutaneous flap. A double free flap reconstruction of such defects is recommended. However, double flap may not be feasible in certain situations. In this study, we objectively evaluated functional and cosmetic outcomes following single soft-tissue flap reconstruction in a group of patients where double flap reconstruction was not feasible. Patient and defect characteristics were obtained from charts. The speech and swallowing functions of patients were prospectively assessed by a dedicated therapist. The cosmetic outcome of reconstruction was evaluated by an independent observer. Fifty-six patients with large soft tissue and segmental posterolateral mandible defect, reconstructed with anterolateral thigh or pectoralis major flap from May 2009 till December 2010 were included. In this series, none of the flaps were lost; two patients with pectoralis major flap developed partial skin paddle loss. Most of the patients developed mandibular drift; however, majority of these patients had no postoperative trismus. All patients resumed regular or soft solid oral diet. The mean speech intelligibility was more than 70%. Majority of patients had satisfactory cosmetic outcome. The defects were classified into regions resected to develop a reconstruction algorithm for optimal reconstruction using a free or pedicle flap. In conclusion, patients with large oro-mandibular defect undergoing single soft tissue flap reconstruction have satisfactory functional and cosmetic outcome. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.