Background: Anterior-posterior thigh diameter measurement via two-dimensional sonography (2D-US) correlates with fetal gestational age and reflects the growth and development of fetal thigh muscles and bones. This measurement, alongside estimated gestational age, offers valuable insights into fetal well-being and growth during pregnancy. This study aimed to evaluate the correlation of gestational age with anterior-posterior thigh diameter measured by two-dimensional sonography and estimated gestational age. Methods: This cross-sectional study was conducted at the Department of Radiology and Imaging, Mymensingh Medical College & Hospital, Mymensingh, Bangladesh from January 2010 to January 2012. As the study subjects, a total of 250 healthy women between the 24th and 38th weeks of normal pregnancy were enrolled by using a purposive sampling technique. For data analysis, SPSS version 23.0 was used. Results: The mean age of the participants was 24.79 ± 4.71 years with a range from 18 to 35 years. More than one-third (34.0%) of the women were in the age range of 21-25 years. The mean gestational age of all participants was 30.93 ± 4.32 weeks. Primigravida accounted for more than half (56.4%) of them. A statistically significant positive correlation was observed between fetal anterior-posterior thigh diameter and gestational age (p<0.001. Conclusion: There is a statistically significant positive correlation between fetal anterior-posterior thigh diameter and gestational age.