The syndrome of the sinking skin flap was introduced to explain the phenomenon of neurological deterioration after decompressive craniectomy. A 37-year-old man was admitted with acute subdural hematoma and traumatic intraparenchymal hematoma. After decompressive craniectomy, the patient suffered from hydrocephalus for which a ventriculoperitoneal (V-P) shunt was inserted. Following this procedure, the depression of the skin flap became remarkable and his mentation was deteriorated. The patient recovered uneventfully after temporary elevating of valve pressure and cranioplasty. We present a patient who was successfully managed with elevation of valve pressure and cranioplasty for the syndrome of the sinking scalp flap with review of a pertinent literature.