We describe three patients with the limb pain of complex regional pain syndrome (CRPS) in childhood with autonomic nervous system function involvement. Their autonomic nerve abnormality was non-invasively examined by means of laser doppler flowmetry (LDF) and a sympathetic skin response (SSR) test. In one it was resolved with physiotherapy, but the others needed epidural anesthesia for pain control. Though CRPS used to be recognized as a refractory disorder in adults, childhood cases have been found in recent years, generally having a better prognosis than adult ones. However, even in the children, the prognosis or responses to the same therapy vary, and there are progressive and refractory cases. CRPS should be considered as a differential diagnosis of unexplained persistent limb pain even in childhood for early and appropriate management.