Canine spinal cords were compressed at T-13 by an epidural balloon maintained at 160 mm Hg for one hour. After seven weeks, mean motor ratings of dogs treated with either parenteral dexamenthasone or non-irrigative local hypothermia (on the dorsal dura mater at 6 degrees C for four hours) indicated ability to walk well, whereas untreated dogs could not walk. A third treatment group received both dexamethasone and delayed local hypothermia; this group performed poorly in early weeks, but eventually surpassed the other groups and became the only group to attain a final mean motor rating which was superior to that of controls at a significance level of p less than .01. Hypothermia was induced by means of a miniature epidural heat exchanger which eliminated tissue irrigation as a possible experimental variable. The possible mechanisms of action of hypothermia are reviewed.