Introduction: Accurate knowledge of the gestational age is essential in management of all pregnancies particularly in cases of high risk pregnancies, electively planned induction of labour, elective caesarean section and to distinguish pre-term from term infants. Aims: To assess the correlation between fetal transverse cerebellar diameter (TCD) and gestational age. Materials and Methods: The present study was a prospective observational study. This Study was conducted from December 2021 to February 2022 at Department of Radio-diagnosis, Nil Ratan Sircar Medical College and Kolkata. Result: In our study, TCD ranged from 15.17mm to 20.86mm between 15-20 weeks, from 21.97mm to 33.90mm between 21-30 weeks and from 34.35mm to 44.52mm and 100 singleton pregnancies of gestational age 15-40 weeks that met the inclusion and exclusion criteria were taken for the study. Conclusion: In this study, the relationship was established between TCD and gestational age between 15-40 weeks.