We developed a new headholder for the fixation and repositioning of patient head in PET study. The device consists of acryl frame and headrest of thermoplastic resin. Special gel is placed on the headrest to adapt different shape of occipit a in each patient. Individual face mask was made with thermoplastic resin just before the PET study and was fixed with the holder using plastic taper. It took about 2-3 min to fix the patient head using these system. Immobilization of the patient's head during PET study was good. Accuracy of repositioning in the same patient was relatively good between separate PET studies.