The results of treatment with thyrotropin-releasing hormone (TRH), naloxone and dexamethasone treatments albino rats with experimental spinal cord injury were compared. All the animals were made paraplegic by the application clip method of Rivlin and Tator. Treatment was administered i.p. as bolus injections in two doses, at 45 and 120 min after the injury. Animals were allocated randomly to four experimental groups: (1) TRH (0.6 mg per dose), (2) naloxone (0.8 mg per dose), (3) dexamethasone (0.6 mg per dose), and (4) control (saline). TRH-treated rats showed significantly better histopathological scores than either naloxone or dexamethasone-treated ones (Kruskal Wallis: 24.058 P less than 0.001).