Heterotopic ossification is a pathologic extra-skeletal bone formation as a form of aberrant repair process with acquired or genetic etiologies. In plastic surgery, it has been well-described in the burn and trauma patients. Rarely, it can happen along the vascular pedicle of free tissue transfer, and when it happens, it is most commonly in head and neck reconstruction. Here we present a case of complete extensive heterotopic ossification of the entire vascular pedicle from the anastomosis to the bone in an osteocutaneous free fibula flap (FFF). The fibula was used as a 2-segment reconstruction for a maxillary defect resulting from a self-inflicted gunshot wound. The skin paddle was used to reconstruct the anterior palatal defect. Heterotopic ossification of the FFF vascular pedicle is most reported in the head and neck reconstruction cases. It is rare, but when it happens, it occurs earlier, more commonly, and more extensively in cases of maxillary reconstruction than in cases of mandibular reconstruction. Flap loss due to this sequela has not been reported, and surgical debridement is indicated only when symptomatic. Heterotopic ossification of an FFF vascular pedicle is a rare but well-described entity. The periosteal bone formation capacity preservation after revascularization of the flap is thought to be one of the major etiologies of this phenomenon. Hence, some have suggested a modification in the harvesting technique of the FFF that could mitigate return to the operating room, especially when it is for maxillary reconstruction in the trauma patient. Keywords: Keywords: free fibula flap, heterotopic ossification, maxillary reconstruction, mandibular reconstruction.