Surgical management of temporomandibular joint (TMJ) ankylosis in children is often challenging and may result in various complications such as facial nerve injury and visible scar. In this clinical report, the authors present minimally invasive management of a 9-year-old boy with bilateral post-traumatic TMJ ankylosis. The ankylotic TMJs were addressed and gap arthoplasties were performed by endoscopically assisted transoral approach. The risk of facial nerve injury is minimized and facial scar was prevented by avoiding extraoral incision. Mandibular movements in 3 directions were satisfactory at 3rd postoperative month.