Objective: This retrospective study aimed to elucidate the histopathological patterns of endometrial biopsies in women presented with abnormal uterine bleeding (AUB) across various age groups in Najran, Saudi Arabia. Methods: A total of 365 subjects, spanning perimenarchal to perimenopausal stages, were included in the study, conducted at the Maternity and Children Hospital in Najran, Saudi Arabia. The study period extended from October, 2020 to September, 2022. Histopathological patterns were analyzed in relation to age, parity, bleeding patterns, cause, and management of AUB. Results: The predominant age group was 40-50 years (40.5%), with proliferative endometrium being the most prevalent histopathological pattern. Menorrhagia was the most common bleeding pattern (34.0%), and functional causes accounted for 46.0% AUB cases. Surgical treatment was the primary management approach (50.7%). Multinomial logistic regression highlighted the unique contributions of age, parity, bleeding patterns, cause, and management of AUB to endometrial histopathology (p < 0.001). Conclusion: The current study findings provided a comprehensive understanding of the complex interplay between demographic and clinical factors in shaping endometrial histopathology in women with AUB in Najran, Saudi Arabia. Tailoring diagnostic and management strategies based on these factors can enhance personalized care for this diverse patient population.