Cytokines, particularly tumor necrosis factor-alpha, may play an important role in the mediation of mechanical hyperalgesia and autonomic signs in complex regional pain syndrome 1. We performed an IV regional block with low-dose administration of the tumor necrosis factor-alpha antibody, infliximab, in a patient with typical clinical signs of complex regional pain syndrome 1 (moderate pain, edema, hyperhidrosis, elevated skin temperature compared with the contralateral side). A significant improvement of clinical variables was observed 24 h after infliximab treatment. Almost complete remission was reached within 8 wk, but sensory signs improved only after 6 mo. No adverse events were observed.