Aims and objectives: To study the possible relationship between abnormal uterine bleeding (AUB) and endometrial thickness in perimenopausal women. Materials and methods: A prospective observational study conducted on 60 cases of AUB in perimenopausal age (41–55 years) group. Results: Institutional incidence of AUB in general and AUB in perimenopausal age was 10.7% and 29.38% respectively. Maximum cases were para 3 and of age 41–45 years (78.33%). Cases presented with irregular and heavy menstrual bleeding (76.66%). About one-third (33.33%) of the study subjects were suffering from severe and life-threatening anemia due to AUB. 90% study subjects required a blood transfusion, maximum of them were transfused preoperatively. As per PALM-COEIN classification, maximum cases had leiomyoma (41.66%) as a structural cause of AUB followed by malignancy and hyperplasia (33.33%). Majority of cases (45%) presenting with AUB had an endometrial thickness between 6–9 mm. Mean endometrial thickness was maximum in cases of AUB M that is 10.33 mm followed by AUB-L 7.56 mm, and AUB-A 7.2 mm. Majority of cases (70%) with ET 9 mm or less were having mild to moderate blood loss. Majority of cases with severe blood loss higher endometrial thickness; half subjects had ET >10 mm, and few had ET 16 to 21 mm. Cafeteria approach for choosing the management line was given. Most of the perimenopausal cases preferred the surgical line of management (83.33%) over medical method (13.33%) despite counseling. Conclusion: Endometrial thickness of more than 7 mm remains a common feature with estrogen-dependent conditions like fibroid, adenomyosis, hyperplasia, and malignancy even during perimenopause. Clinical Significance: AUB in perimenopause needs vigilant surveillance, and endometrial thickness may be a relevant tool for it.