Single photon emission computed tomography with N-isopropyl-p-[I-123]iodoamphetamine was performed in 13 cases of craniosynostosis before and after surgery. Of 13 cases, 8 cases (62%) showed focal low perfusion area on preoperative study. Four of seven cases (57%) with brachycephaly showed low perfusion areas in either of frontal lobes, occipital lobes, and cerebellum. Besides, two patients with scaphocephaly and one with plagiocephaly showed low perfusion area in unilateral cerebral hemisphere. Two Crouzon disease cases showed no focal low perfusion area, but an Apert disease showed low perfusion areas in both frontal lobes, cerebellum, as well as left occipital lobe. Corresponding CT and MRI showed no focal abnormality in any of these cases. These low perfusion areas were diminished or disappeared after surgical treatment in 6 cases (75%). We concluded that the I-123-IMP-SPECT is considered to be a useful index for the evaluation of functional recovery after surgery in cases with craniosynostosis.