A 24-year-old woman presented with progressive optochiasmatic arachnoiditis causing progressively worsening visual loss associated with headache and amenorrhea. Treatment with the standard initial therapy of dexamethasone, warfarin, and dipyridamole was unsuccessful at halting her disease process. Surgical lysis of adhesions led to a temporary improvement and then deterioration. A course of therapy with cyclophosphamide was initiated and her response to this therapy resulted in resolution of her headaches, return of her vision to normal, and resumption of her normal menstrual cycles.