Background: Abnormal uterine bleeding (AUB) is prevalent among perimenopausal women, necessitating accurate diagnosis for effective management. The FIGO PALM COEIN classification system aids in identifying underlying causes of AUB.Aim: This study aims to categorize AUB causes in perimenopausal women using the FIGO PALM COEIN classification system.Study Design: A hospital-based prospective observational study was conducted involving 200 perimenopausal women aged 40 and above, within one year of menopause, presenting with complaints of AUB to the gynecology department at AVMC.Methods: Clinical diagnosis using the FIGO PALM COEIN system, supplemented by investigations and endometrial sampling, was conducted. Data were analyzed using descriptive statistics.Results: Participants (mean age: 45-50 years) predominantly presented with leiomyoma (41.5%), followed by polyps (23%), endometrial abnormalities (17.5%), malignancies/hyperplasia (9%), and ovulatory dysfunction (6%). Adenomyosis, iatrogenic causes, and coagulopathy were less common. Normal ultrasonography results were observed in 40.5% of cases. Endometrial hyperplasia (24.5%) and adenocarcinoma (15.09%) were detected histologically. Polyps (18.5%)and fibroids (8.5%) were identified via ultrasonography.Conclusion:The study underscores diverse AUB causes in perimenopausal women and advocates for ultrasonography incorporation in initial assessments, followed by endometrial sampling when indicated. PALM components played a significant role in categorizing AUB clinically, with leiomyoma as the primary cause. However, histological testing revealed a higher prevalence of PALM-related causes. © 2024 Elsevier B.V., All rights reserved.