Aim: For any unsuspecting woman, the finding of an ovarian cyst/mass that has the potential to be either malignant or end up in a cyst accident (torsion, rupture, or hemorrhage) and hence requires intervention, is of paramount importance. Based on ultrasound-guided explicit criteria, this study was aimed at determining the prevalence of abnormal ovarian masses, both malignant and benign, in the most vulnerable age group. Materials and methods: A community-based; descriptive cross-sectional study was conducted among 931 females aged over 40 years who were selected by probability proportionate to the cluster sampling technique. All the study participants underwent trans-abdominal ultrasound scanning. Married subjects were offered a subsequent transvaginal scan (TVS) if indicated. Results: The prevalence of abnormal ovarian masses based on ultrasound assessment was 2.9% [95% confidence interval (CI): 1.8–4.0]. Thirteen subjects (1.4%) had complex cysts between 3 and 5 cm diameter (95% CI: 0.8–2.3) and five (0.53%) had complex cysts larger than 5 cm (95% CI: 0.2%–1.2%). The prevalence of simple ovarian cysts exceeding 5 cm was 0.97% (95% CI: 0.5–1.8). Histopathological examination of abnormal ovarian masses that needed surgery revealed; endometrioma (n = 6), mature cystic teratoma (n = 1), mucinous cyst adenoma (n = 1), serous cyst adenoma (n = 1), and serous papillary cyst adenocarcinoma (n = 1). Conclusion: Abnormal ovarian cysts/masses were more prevalent among women aged above 50 years, and those who had attained menopause. Pelvic ultrasound assessment of women in their 50s belonging to potential high-risk groups can be recommended on an annual basis.