Background: Abnormal uterine bleeding in peri- and postmenopausal women often raises concern for underlying pathology such as endometrial hyperplasia or carcinoma. This study aimed to evaluate the correlation between endometrial thickness on transvaginal ultrasonography and histopathological findings in postmenopausal bleeding. Aim of the study: The aim of the study was to evaluate the correlation between endometrial thickness on transvaginal ultrasonography and histopathological findings in postmenopausal bleeding, identifying predictive relationships for clinical assessment. Methods: This cross-sectional study was conducted at the Department of Obstetrics and Gynaecology, Dhaka Medical College Hospital (DMCH), Dhaka, Bangladesh, from June 2022 to May 2023, including 65 postmenopausal women with vaginal bleeding. Transvaginal ultrasonography (TVS) was performed to measure endometrial thickness, followed by fractional curettage for histopathological analysis at the Department of Pathology, DMC. Data were analyzed using SPSS version 26, and patients were categorized by endometrial thickness (≤5 mm or >5 mm), with statistical significance set at p < 0.05. Results: Among 65 postmenopausal bleeding patients, 58.5% had endometrial thickness >5 mm (mean 9.1 ± 6.1 mm). Histopathology showed 70.8% had abnormal findings, mainly endometrial hyperplasia (47.8%). A significant association (p = 0.001) was found between endometrial thickness and pathology, with >5 mm thickness linked to hyperplasia, carcinoma, and polyp, and ≤5 mm thickness linked to atrophy. Conclusion: Endometrial thickness on transvaginal ultrasonography is a significant predictor of endometrial pathology in postmenopausal bleeding, aiding in clinical assessment.