This one-year prospective study was carried out at a tertiary care hospital in Ludhiana, Punjab, on patients visiting antenatal OPD (Outpatient Department) in the third trimester with clinical suspicion of IUGR (Intrauterine Growth Retardation) by using high resolution Doppler ultrasound scanner, Model EUB-450, Hitachi. The objective of this study was to evaluate the role of ultrasound in detection of intrauterine growth retardation and to assess and compare different parameters in order to determine best ultrasonic parameter to assess IUGR. The patients included were studied under two groups: Test group of patients suspected to have IUGR on obstetrical examination (n=75) and control group of 148 subjects showing signs of normal foetal development, i.e. not suspected to have IUGR clinically. Four parameters were taken into account namely the Abdominal Circumference (AC), ratio of AC and head circumference (HC:AC), ratio of AC and femur length (FL:AC) and umbilical artery systolic to diastolic ratio (S:D). The sensitivity of ultrasound in detecting IUGR was 86.9%. Umbilical artery flow velocimetry correctly identified 24 of 46 IUGR infants, but on no occasion did this technique detect IUGR, otherwise missed by real time sonography. The sensitivity and specificity of all the four parameters can be summarized as: AC -82.6% and 89.6%, HC: AC -50% and 86.2%, FL:AC -47.8% and 82.7% and umbilical artery S:D ratio -52.1% and 93.1%. Five patients showed absent diastolic flow and three patients showed reversal of diastolic flow. None of the fetus survived in whom there was reversal of flow. We conclude that sonography is a safe, reliable, non-invasive tool in assessment and management of suspected IUGR at or beyond 32 weeks of gestation for obstetrician and the neonatologist. KEYWORDS IUGR, Umbilical Artery Flow Velocimetry.HOW TO CITE THIS ARTICLE: Singla S, Gaind RK, Sagoo HS. Role of real time ultrasound and Doppler study of umbilical artery in evaluation of intrauterine growth retardation.