Background: Accurate prenatal estimation of birth weight is useful in the management of labour and delivery. Objective: To determine the correlation between clinical estimated fetal weight with actual birth weight in 3rd trimester of pregnancy and to determine the correlation between Ultrasonographic fetal weight assessment with actual birth weight in 3rd trimester of pregnancy. Material & Methods: This cross sectional study with non-probability purposive sampling technique was conducted in three tertiary care hospitals of Punjab, Department of Obstetrics & Gynaecology, Allied Hospital, Faisalabad, Lady Aitcheson Hospital Lahore and Lady Willington Hospital Lahore. Informed consent was obtained from each female to use their data for research purpose. Demographic details were also noted. Then females undergo CEFW was done by using Johnson's formula. Then ultrasonography was done on every female by experienced radiologists to get UEFW. FW measurement was done by using Shepard formula. Then females were followed-up till delivery of fetus. Actual birth weight (ABW) was noted on birth. Pearson correlation was used to measure the correlation coefficient for CEFW and UEFW with ABW. P-value≤0.05 was taken as significant. Results: In our study the mean age of the patients was 29.60±6.23 years and the mean gestational age of 33.30±2.31 weeks. The mean BMI value of the patients was 23.08±1.26 Kg/m2, the mean CEFW value 2219.60±556.41 grams while the mean UEFW value of the patients was 2227.77±521.94 grams and the mean value of ABW of the patients was 2284.00±515.29 grams. In our study the positive correlation was found between the CEFW, UEFW with ABW of the baby. Conclusion: Our study results concluded that both the clinical estimation ultrasonography estimation showed the feasible and reliable results. Both showed positive correlation with actual birth weight.