Background: The assessment of fetal growth is a critical component of prenatal care, enabling identication of fetuses at risk of perinatal morbidities and mortality. The fetal weight determination using ultrasound is one of the best indicators of fetal growth, however its accuracy is still questionable as it is affected by multiple anthropometric and genetic factors. Very little information is available regarding the effectiveness of the currently used western population-based models in calculation of fetal weight in Indian scenario. Our study aimed to evaluate the accuracy of Aim: prenatal ultrasound in calculation of estimated fetal weight in third trimester using pre-natal ultrasound at a tertiary care center in Rajasthan, India. Materials and Methods: Descriptive type of observational study was done at a tertiary care hospital in Rajasthan. 73 pregnant females were evaluated with estimated fetal weight (EFW) calculation using Hadlock 2 (AC, BPD, FL) formula and compared with actual birth weight. Results: Positive correlation existed between EFW and ABW with spearman's rho coefcient=0.615, p value <0.001. This difference in weight by ultrasound and actual weight was found to be statistically signicant (t=3.094, Df=144, p value<0.002). Our study was one of the very Conclusion: few studies which demonstrated that statistically signicant differences existed between the estimated fetal weight on USG and the actual birth weight on the basis of the currently used fetal weight estimation formulas which are based on foreign populations. High percentage error was noted in the calculation of fetal weight which may be due to a lot of factors like- fetal head position in pelvis , machine quality, maternal obesity, maternal restlessness during scan, excess fetal movements, subjective variations etc.