Intrathecal methylprednisolone acetate (IT-MPA) treatments have been reported to be beneficial and safe for the treatment of low back problems and especially "failed back" problems, which include adhesive arachnoiditis. Other reports, however, have stressed the potential dangers of this treatment and have advised against its use. Many of these papers implicate the propylene glycol included in the methyl-prednisolone as being potentially harmful. Since the literature is rather extensive and clearly conflicting, it is difficult for those who treat patients with "failed back" problems to ascertain the risk/benefit ratio of this form of treatment, so a literature review and analysis has been undertaken. Published literature clearly attests to the usefulness and general safety of IT-MPA when used within certain limits. Although several studies implicate IT-MPA as a potential cause of arachnoiditis or other neurologic injury, most of the evidence is circumstantial and most complications followed multiple, large-dose, or frequent injections.