Background: Placenta is the vital support organ for the developing fetus which provides the physiological link between a pregnant woman and the fetus. Placental thickness was measured at the level of insertion of umbilical cord and is correlated to gestational age measured by known parameters like BPD, HC, AC and FL. Materials & Methods: A total of 100 women between 20–40 years of age group and 11–40 weeks of gestation with singleton pregnancy were included in the study. PHILIPS EPIQ 7G ultrasound machine with a curvilinear probe of 3-5 MHz frequency was used. The composite average of the gestational age was estimated automatically by software by using bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL). The placental thickness was measured at the level of the insertion of umbilical cord. Results: Present study shows a linear correlation between mean placental thickness and gestational age. Placental thickness lags behind gestational age from 37 weeks which is attributed to reduced blood supply to placenta near term. Conclusion: The estimation of the placental thickness is a significant parameter for estimation of fetal age specially in late mid trimester and early third trimester where the exact duration of pregnancy isn't known and other sonographic parameters additionally become less dependable.