We present a case of cystic meningioma accompanied by hemorrhage in the cyst and adjacent subarachnoid space that occurred while preoperative embolization in feeders of the tumor was being applied. The possible reason for the hemorrhage was the sudden dynamic changes in blood flow triggered by the embolization. The changes could have caused multiple ruptures of pathologic small vessels. We recommend that preoperative embolization should be used cautiously in treating cystic meningiomas because of a possible increase in bleeding from pathologic weak vessels.