Eleven patients (two male, nine female) were treated with epidural sympathetic blockade for reflex sympathetic imbalance, an incomplete manifestation of reflex sympathetic dystrophy. Each had developed severe pain, sensitivity, and disability disproportionate to associated trauma. One patient injured an ankle, and the remaining 10 patients one or both knees (12 knees). Seven patients had undergone previous surgery. All but one had a favorable response to initial blockade. This individual eventually failed treatment despite surgical sympathectomy. Seven have required readministration of a block for clinical relapse. Mean followup was 22 months (range, 10 to 41 months). Five underwent extensive psychological testing. All have required adjunctive forms of therapy including physical therapy, transcutaneous electrical nerve stimulation (TENS), antiinflammatory or other nonnarcotic agents. Recovery is typically prolonged, particularly if the diagnosis is delayed. Close attention to, and therefore prevention of, situations that trigger its recurrence is essential for successful rehabilitation.