Background: This study was performed to find out whether transcutaneous bilirubinometry could be a valid screening method for hyperbilirubinemia in preterm infants, especially for those who needed mechanical ventilation. Methods: We evaluated 63 preterm Iranian newborns who were managed in the neonatal intensive care unit of Shahidbeheshti University Hospital, Isfahan, Iran from April 2009 to April 2010. Transcutaneous bilirubin (TCB) measurements were obtained using BiliCheck™ shortly before or 10 minutes after taking blood for determination of the plasma bilirubin level in premature newborns, who did not receive phototherapy. We assessed the correlation between the transcutaneous bilirubin and plasma bilirubin level by linear regression analysis. We also analyzed the gestational age, birth weight, postnatal age, sex, and hematocrit, for determination of their effect on transcutaneous bilirubin accuracy. Results: The overall bilirubin concentration ranged from 5.4 to 17 mg/dL and from 4.8 to 17.3 mg/dl for total serum bilirubin (TSB) and transcutaneous bilirubin, respectively. The mean values obtained by transcutaneous bilirubinometry were slightly higher than the total TSB values. The correlation coefficient between TSB and TCB was r=0.82, P<0.001, and this was not influenced by gestational age, postnatal age or hematocrit, which were previously considered to be important. The correlation coefficient between TSB and TCB in mechanically ventilated preterm infants was r=0.75, P<0.001. Conclusion: Plasma bilirubin level can be accurately measured by BiliCheck™ in premature newborns, even in newborns who need mechanical ventilation.