Introduction: Abnormal uterine bleeding (AUB) is bleeding from the uterus that is longer than usual or that occurs at an irregular time. Bleeding may be heavier or lighter than usual and may occur often or randomly. In most women, AUB is caused by a hormone imbalance. Any woman over the age of 40 years with menorrhagia or any other forms of abnormal vaginal bleeding should undergo a gynaecological check and an endometrial biopsy as indicated, in order to detect a potentially treatable cause as atypical endometrial hyperplasia and early endometrial carcinoma. The present study was done on women with AUB to evaluate the histopathological patterns in endometrial biopsy among different age groups. Materials and Methods: A cross-sectional study was carried out in Department of Pathology, Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune. The clinical history and findings of 100 patients were collected and recorded. Histopathological study of endometrial patterns and age specific correlation was done. Results: Out of a total of 100 patients of AUB, 72 of them had a functional cause and the remaining 28 patients revealed an organic cause. The mean affected age was 40 years with youngest being 21 years old and the oldest patient was 57 years of age. Functional causes constituted 72% and organic lesions were seen in 28% out of which Proliferative phase endometrium was the most common functional lesion observed while endometrial hyperplasia was the commonest organic pathology seen. P value was calculated as <0.008 which was significant using chi square for trend seen in age. Conclusion: Histopathological examination of endometrial biopsy in patients of AUB is considered as a gold standard of patient evaluation, diagnosis and management and avoids any future complications.