To develop gender and gestation-specific growth percentiles for singleton live-born neonates and to compare new weight for age unisex percentiles with Lubchenco unisex percentiles. Cross-sectional birth data were collected from the neonatal registry from January 2000 to April 2006 (n = 15.509). After exclusion, the sample included 15.112 neonates. Newly developed weight for age, charts were compared with Lubchenco unisex percentiles, 91.8% of the subjects were classified in the same way (Kappa

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... 0.74, P < 0.001). Small for gestational age (SGA) and large for gestational age (LGA) according to the Lubchenco percentiles differed from the new percentiles (Mc Nemar test, P < 0.001). The percentage of SGA neonates was underestimated by Lubcheno percentile (5.8% vs. 10.6%, respectively), whereas the percentage of LGA neonates was overestimated by Lubcheno percentile (10.3% vs. 9.3%, respectively). New growth chart for newborn delivered at different gestational ages have been established, which can be used to define SGA and LGA in Turkish neonates. Studies comparing the Lubchenco percentiles with new percentiles are needed.