Introduction: The transoral mandibular tongue-splitting approach is typically performed for the treatment of upper cervical tumor and instability but has not been performed for the treatment of upper cervical epidural abscess (UCEA). We report the first case of UCEA successfully treated with a transoral mandibular tongue-splitting approach. Technical Note: A 62-year-old man who had medical histories of tracheotomy with intubation and dermatopathy due to radiation therapy for the treatment of nasopharyngeal carcinoma presented with neck pain and limb weakness. The imaging examination revealed bone erosion of C2-C4 vertebrae and abscess at the level of C2-C4, supporting a diagnosis of UCEA. The transcervical approach could not be used for treatment; therefore, the transoral mandibular tongue-splitting approach was used successfully to perform decompression, debridement, and iliac bone grafting. Subsequently, we reviewed the literature pertaining Transoral Mandibular Tongue-Splitting Approach 2 to the use of the transoral mandibular tongue-splitting approach. The approach can be invasive and cause some complications. However, no fatal complications have been reported, and all patients demonstrated a favorable neurological outcome with reduced neurological deficits. Conclusions: This case and subsequent literature review suggest that the transoral mandibular tongue-splitting approach may be effective for the improvement of neurological outcomes without fatal complications in patients with UCEA. There may be an increasing number of patients with UCEA requiring the transoral mandibular tongue-splitting approach due to the increasing prevalence of immunocompromized status and the aging population.