Background: In some countries, third-trimester ultrasound monitoring of foetal growth is a standard practice, increasing detection rates to 40-80%. Objective: Evaluation of the effectiveness of standard third-trimester ultrasound examinations at 36 weeks' gestation with those at 32 weeks' gestation for detecting fetal growth restriction (FGR). Patients and Methods: 132 women who meet the inclusion criteria. Biparietal diameter, head and abdominal circumferences, and length of the femur were used to calculate the estimated fetal weight (EFW). It was determined that an immediate Doppler assessment of the umbilical artery pulsatility index from a free-floating umbilical cord section was necessary when EFW was less than 10th centile by local standard. Automated pulse Doppler measurements were made. After delivery, neonates were assessed by pediatrician to assess fetal growth. Results: There was a statistical significance increase in EFW at 36 weeks of gestation compared to values at week 32. All US parameters had significant validity in predication of fetal growth restriction (FGR) but with higher accuracy in differentiation than that assessed at 32 weeks of gestation, the most precise was abdominal circumference (AC with) 59.1% accuracy, 65.9% sensitivity and 48.3% specificity for negative cases, then 55.7% and 51.5% for FL and BPD respectively. Conclusion: Detection of FGR and related perinatal and neonatal outcomes was more accurate when ultrasound was performed at 36 weeks' gestation than when it was performed at 32 weeks' gestation.