Permanent paralysis was induced in dogs by a 500 gram centimeter force injury on the spinal cord, and drug treatments were given 1 hour after injury and were continued for 3 days. Dogs were evaluated for 90 days. Isotonic saline or mannitol administration were ineffective in reversing the paralysis. In dogs receiving either dimethyl sulfoxide or dexamethasone, six of eight animals in the former and two of eight in the latter group regained partial or full recovery. The presence of somatosensory evoked responses taken before and at various intervals following trauma showed a good correlation in the prognostic recovery of each animal. It is concluded that dimethyl sulfoxide and dexamethasone can reverse a permanent experimental injury to the spinal cord when given within an hour after trauma.