Background: The thickness of the placenta when used together with other parameters can improve the accuracy of the assessment of the gestational age of the fetus. The present study was determining gestational age by USG GA of placental thickness and its correlated with LMP gestational age in central Indian population. Methods: This was an observational cross sectional study conducted in the Department of Radiology in collaboration with Department of Anatomy at L.N. Medical College and Research Centre, Bhopal. A total of 100 central Indian women in the second trimester of pregnancies were selected for the study. The placental thickness was measure using Toshiba ultrasound equipment with a 3.75 MHz curvilinear transducer Results: The correlation between 2nd trimester LMP & placental thickness gestational age, which is found to be highly correlated (Pearson Correlation value .971) and it is statically significant (P value – 0.01) Conclusion: It can be concluded from the result that the thickness of the placenta was a less accurate parameter for assessing the gestational age in 2nd trimesters compared to other parameters