Objective: The present report describes an alternative technique of using a flow- through, double-paddle, fibular, osteocutaneous free flap based on one perforator from the peroneal system and one perforator from the anterior tibial system for a through-and-through mandibular defect. Methods: The patient was a 65-year-old man who underwent a composite resection of the floor of the mouth, mandible, and chin pad due to recurrent oral cavity squamous cell carcinoma. The fibula was harvested with one posterior-lateral septal perforator from the peroneal system and with a second skin perforator from the anterior tibial system to perfuse a 15 × 14 cm skin island. The anterior tibial perforator was anastomosed to the distal end of the peroneal artery in a flow-through technique, and the area between the peroneal and tibial perforators was de-epithelialized to reconstruct separately the floor of mouth and cutaneous defects. Results: Good inflow and outflow of both skin islands were noted at the end of the procedure, and the patient recovered successfully without any fistulas or donor site morbidity. Conclusions: Perforators from the anterior tibial system should be considered for large, through-and-through mandibular defects when using 2 perforators from the peroneal system is not possible. In addition, we believe the flow-through technique can be useful in patients with vessel-depleted necks and provides a suitable match for vessel size between an anterior tibial perforator and the distal end of the peroneal system.