Two thirds of patients suffer from moderate to severe pain after frontotemporal craniotomy. We think neurosurgeons must try to reduce the postoperative pain, which may induce postoperative hypertension, restlessness, and pathological pains. To investigate how preemptive analgesia effects postoperative pain, we assessed the pain in 20 consecutive patients who underwent neck clipping for non-ruptured cerebral aneurysms of anterior circulation systems by frontotemporal craniotomies. Ten patients underwent preemptive analgesia with four procedures (preemptive group) as follows, 1) oral administration of long-acting non-steroid anti inflammatory drug (NSAID, ampiroxicam) two hours before the surgical operation, 2) nerve blockades of the supra-orbital nerve and the infra-orbital nerve by bupivacaine, 3) local anesthesia of the scalp along the marker of a skin incision by xylocaine, 4) local anesthesia by bupivacaine along a skin incision after the skin closure. Ten patients of the control group underwent only procedure No.3. Visual analog pain score (VAS) for postoperative pain 6, 12, and 24 hours, and 3, 5, 7, and 14 days after operation and NSAID administration for the pain were evaluated. Patients of the preemptive group had significantly less postoperative pain during the whole post-surgery period and required less administration of NSAID than the control group. Preemptive analgesia procedures No.1, 2 and 4 reduced the postoperative pain and the total administration of NSAID. Postoperative pain may be reduced after other types of brain surgery with proper nerve blocks like procedure No.2, procedures No.1, 3 and 4.