Description of a series of cases in which otogenic encephaloceles in patients requiring canal wall down (CWD) mastoidectomies were repaired via a transmastoid approach. Case series. Tertiary-care hospital. Eleven cases of otogenic encephaloceles in patients requiring CWD mastoidectomy for chronic ear disease. Surgical repair of an otogenic encephalocele using a transmastoid approach. Success of repair, number and size of defects, materials used for repair, complications encountered in surgery, pure tone average air-bone gap (PTA-ABG). Eleven cases were identified. Two of these patients had a prior CWD cavity while the remainder received CWD mastoidectomy simultaneously with encephalocele repair. None of the patients required revision of encephalocele repair. Mean preoperative PTA-ABG was 30 dB and mean postoperative PTA-ABG was 28 dB (p = 0.66). A single-stage strictly transmastoid approach to otogenic encephalocele repair may be effective in patients with prior CWD mastoid cavities or requiring concurrent CWD mastoidectomy for chronic ear disease and/or cholesteatoma.