To evaluate intracranial venous haemodynamics in craniosynostosis noninvasively, we measured the blood flow velocities and pulsatility indices in the superior sagittal sinus (SSS) and the middle and the anterior cerebral artery during the perioperative course in 21 children undergoing repair of craniosynostosis involving the midline sutures, using transcranial colour-coded duplex sonography (TCCS). An age-matched group of 12 healthy children was examined in like manner for comparison. In the healthy group, the mean pulsatility index (PI) in the SSS was 0.22 and the mean resistance index (RI) 0.20. The mean preoperative PI and RI in the synostosis group were significantly higher [0.41 and 0.34, respectively (P<0.01)], but fell to 0.19 and 0.17 (P<0.01) in the postoperative course. Our results indicate that in craniosynostosis there is an altered venous haemodynamics in the SSS, which can be observed noninvasively by TCCS.