Reversible cerebral vasoconstriction syndrome (RCVS) is a heterogeneous group of cerebrovascular disease. The pathophysiology of RCVS is unknown, but a disturbance in cerebral vascular tone is one of hypothesis. Long-term use of Gonadotropin-releasing hormone (GnRH) agonists can induce a pseudomenopausal state in which estrogen production are suppressed. It might lead to reduced arterial relaxation by estrogen withdrawal. We report a case of RCVS after the injection of synthetic analogue of GnRH.