Background: A healthy foetus requires the normal growth of the placenta during the pregnancy. On the other hand,, any disturbance related to its maturation may have a major effect on the fetal growth and the pregnancy outcome. Aim of the work:To detect the relation between the umbilical artery Doppler, placental thickness, and foetal growing. Patients and methods: This cross-sectional study conducted at the outpatient clinic of the obstetrics and gynecology department, Al-Azhar University hospitals (assuit) and AL_Eman General Hospital. Results: At the first visit, there was a strong positive connection between placental thickness and AC, BPD, and HC (r=1.00, p<0.001). At the second visit, There were a notable positivity correlation between placental thickening and estimated foetal weight and umbilical flow by the Doppler (r=1.00, p<0.001). Conclusion:Estimating the fetal weight is essential in our daily obstetric practice, especially at the third trimester. It helps the obstetricians in making decisions about delivery time and mode of delivery, to protect against the complications of low birth weight and macrosomic babies during labor and puerperium. From the findings of this study we can conclude that, there is measurably critical positive relationship between placental thickness and EFW, BPD, FL, AC and umbilical flow by the Doppler. Estimation of the placental thickness by Ultrasound is a good predictor for foetal growth and birth weight.