A case of adenocarcinoma of the nasal septum is reported. The patient was a seventy-one year old female who had developed a nasal obstruction with swelling around nasal radix. Physical examination reveated that the bilateral nasal septum was enlarged with a tumor mass. She was treated surgically by an external nasal approach under general anesthesia. Pathological findings showed adenocarcinoma originating from the nasal septum. Carcinoma of the nasal septum is very rare. In Japan, only fifty eight cases have been reported to date. Including this case, only six cases of adenocarcinoma have been reported. Clinical features and treatment are briefly reviewed.