The diagnosis of reflex sympathetic dystrophy is based on clinical presentation and often the presence of a positive three-phase technetium bone scan result. This study compared vasomotor control patterns between reflex sympathetic dystrophy patients with positive bone scan results and those with negative results. Both groups showed similar vasomotor responses to isolated cold stress testing--warm, cold, and transitional patterns of response were identified in both groups. Thus, this study demonstrates that a positive technetium bone scan result does not correlate with vasomotor disturbances in patients with reflex sympathetic dystrophy of the hand.