Background: Abnormal uterine bleeding describes any variation from normal bleeding patterns in nonpregnant, reproductive-aged women beyond menarche lasting for at least 6 months. The management of abnormal bleeding can involve many decisions about diagnosis, aetiology and treatment, which often occur simultaneously and without the benefit of comprehensive, evidence-based guidelines. The purpose of the study was to evaluate and detect the causes of Abnormal Uterine Bleeding and its Management in a Tertiary Level Hospital. Methods: This is a cross-sectional type of descriptive study, conducted in Shaheed Suhrawardy Medical College Hospital over six-month duration. Sample was selected by purposive sampling technique. Women with abnormal uterine bleeding admitted in Obstetrics and Gynaecology Department, Shaheed Suhrawardy Medical College Hospital were included. Total100 patients were included. Results: In this study, the maximum numbers of cases (52.0%) were between 36-45 years age group. Mean age was 34.57 ± 9.27 years. Per vaginal bleeding was most common symptoms, present in 100% cases; next common symptoms were abdominal pain (76%), lump in lower abdomen (26%). On evaluation of types & causes of AUB, maximum patient belongs to AUB-L (leiomyoma) group (40%) followed by AUB-A (adenomyosis) (20%); AUB-P (polyp) (8%); AUB-O (ovulatory) (30%) and AUB-M (malignancy) (2%). Total abdominal hysterectomy only done in 31.0% patients, total abdominal hysterectomy with unilateral salpingo-oophorectomy was done in 9.0% patients and total abdominal hysterectomy with bilateral salpingo-oophorectomy was done in 60% patients. Conclusion: Present study concluded that most common cause of AUB was leiomyoma followed by adenomyosis. This classification system helps in understanding various exact etiological causes of AUB and can be used by the clinicians, investigators and even patients themselves to facilitate communication, clinical care and research. For this reason we strongly recommend adoption of this classification for AUB and HMB.