Background: Doppler studies of the fetal circulation have demonstrated the importance of the ductus venosus in the continuous monitoring of fetuses, especially those of high-risk pregnancies that can lead to abnormal pregnancy outcome. We tried to put reference values for the normal ductus venosus (DV) flow in normal gestation to be used in further studies assessing the different pathologies. Results: The DV length ranged from 9.8 to 20.9 mm, and the diameter ranged from 0.6 to 2.3 mm. The DV pulsatility index, resistive index, and systolic velocity/maximum velocity during atrial wave ratio declined linearly with increasing of gestational age and were increased after that during the last weeks of pregnancy. Ductus venosus S wave and A wave velocities increased linearly from a mean of 38.30 at the first trimester to 61.68 at the third trimester and from a mean of 11.38 at the first trimester to 30.71 at the third trimester respectively. Conclusion: A reference range of the normal ductus venosus different Doppler parameters was constructed in a centile module.