Background: Measurements of CVO2 may improve our understanding of cerebral oxygenation in neonates. We aimed to evaluate a non-invasive method for the estimation of CVO2 using near infrared spectroscopy (NIRS), and to investigate the relationship between gestational age and CVO2Subjects: 20 babies, aged< 1 week, M:F = 9:11, median (range) Gestn = 27 (24-41)w, median (range) B Wt = 1.1 (0.5-3.6) Kg .Measurements: Cerebral haemoglobin flow (CHbF) and cerebral venous oxyhaemoglobin saturation (CSvO2) were measured using NIRS. Arterial oxyhaemoglobin saturation (SaO2) was measured by pulse oximetry. CVO2 was calculated from: CVO2 = CHbF x(SaO2 - CSvO2) x 4 Results: Median(range) CVO2 was 23.14 (8.6 to 78.5) μmol/100 g/min (0.519 (0.194 to 1.76) ml/100 g/min). CVO2 increased with gestational age (n =20. r = 0.71, p = 0.0004). Conclusions: CVO2 can be estimated in neonates using this non-invasive method. The values obtained are consistent with the few previously published values and with values expected from the known rate of cerebral glucose consumption in neonates. CVO2 increases with increasing brain maturity.