Objectives: The aim of this study was to evaluate whether transcerebellar diameter (TCD) in singleton gestations can serve as a reliable predictor of gestational age (GA) in fetuses in the third trimester between 31-36 weeks of pregnancy in women attending the antenatal care clinic for routine ultrasound examination. Patients and Methods: This was a prospective observational study conducted on pregnant women attending our ultrasound unit for routine antenatal care at Benha University Hospital. The study was conducted after obtaining approval from Local Ethics Committee on research involving human subjects of Benha Faculty of Medicine form December 2021 to October 2022. Results: There was statistically significant positive correlation between GA by LMP with GA by BPD and GA by TCD, GA by FL as well as GA by AC. TCD had highest correlation with value of 0.969. There was statistically significant positive correlation between GA by TCD with GA by LMP and GA by BPD, GA by FL as well as GA by AC. Conclusion: According to the study, TCD is the most accurate method for determining gestational age in the third trimester, followed by FL, and BPD is the least accurate. Additionally, even in cases where patients are unaware of their dates, we may be fairly positive of gestational age by combining the accuracy of TCD (89%) and FL (79%)