Accurate knowledge of gestational age is the key for successful antepartum care and critical interpretation of antenatal tests and successful planning of appropriate intervention. Ultrasound scanners have given a number of ultrasonic biometric parameters to determine gestational age. The most commonly used are CRL, BPD, HC, AC, FL to determine gestational age, fetal weight, and growth in different trimesters. Since fetal growth is very rapid, parameters change significantly with gestational age and must be evaluated against normal tables or graphs. The prenatal measurement of fetal parameters vary among different populations, depending upon their racial demographic characteristics. Biometric curves for one population may overestimate or underestimate the fetal age when used for another population with different demographic characteristics. Unfortunately, the obstetrical tables used in our country are produced from the data collected in the population of developed countries which may vary from our population. Therefore, the present study was undertaken to assess gestational age with the help of USG measurements in the local population (Jaipur zone) of Rajasthan