Estimated fetal weight has a great significance in obstetrical ultrasound, as this gives the information about fetal growth and assist in planning the mode of labour management. Various formulas are used for estimating the fetal weight. Vintzileos’ formula, in which there is an addition of fetal thigh circumference along with biparietal diameter, abdominal circumference and femur length correlates well with actual birth weight however it is slightly less accurate in predicting the birth weight than Hadlock’s formula. Objective: To correlate the fetal thigh circumference at 36-40 weeks ultrasonographically with birth weight. Method: A cross sectional analytical study involving 236 patients was conducting in the radiological department of Mansoorah Hospital, Lahore, Pakistan using Toshiba Nemio 30 with 2-5 MHz transducer. Results: Mean of actual birth weight is 3.3424 + 0.42374 which is different from the mean of EFW by Vintzileos i.e. 3.4504 + 0.08968 whereas it is similar to mean of Hadlock’s formula i.e. 3.3199 + 0.35452. Correlation between EFW by Vintzileos’ formula and actual birth weight is 0.319 more significant than the correlation between EFW by Hadlock’s formula and actual birth weight i.e. 0.300. Conclusion: Hadlock’ formula is more accurate in predicting the actual birth weight than the Vintzileos’ formula. However, due to its stronger correlation with birth weight thigh circumference can be used as an alternative parameter to biparietal diameter for estimating the birth weight at or near term when biparietal diameter becomes difficult to measure because of fetal head position down to pelvic bone.