A 60-year-old male presented with normal pressure hydrocephalus following subarachnoid hemorrhage and underwent a shunt operation. However, a shunt effective range was so narrow that he repeated a sign of overdrainage and underdrainage of CSF. At the result, reflex sympathetic dystrophy (RSD) as a complication of overdrainage was demonstrated. We could prescribe appropriate shunt flow rate by using siphon control system instead of antisiphon device (ASD) and then avoid shunt malfunction. In addition, medication of Neurotropin for pain control of RSD was so effective. We report a case of RDS as a complication of shunt malfunction.