Birth weight is an important predictor of neonatal problems since infants who .deviare from physiologic norms of weight for gestational age have increased perinata1 mortality. The introduction of ultrasonic techno1ogy to obstetrics allows a reasonable precision in fetal weight prediction. This study is a clinical trial to evaluate the accuracy of the rea1-time ultrasono. graphic estimation of fetal weight by measurements of biparietal diameter and fetal abdominal circumference. The accuracy of estimating fetal weight with reaI-time ultrasonography was studied in 58 fetuses. The technique was described and results were compared with those of others . High degree of correlation(r=0.922) was found between actual and calculated birth weights .The absolute mean error was 188.3gm or 6.1% of the mean weight 82.8% .of the measurements fall with in 10% of the actual birth weight . The estimates were more accurate in the low(tiny) weight group . 60.3% of the measurements were underestimated.