Background: Upper Gastrointestinal Bleeding (UGIB) is a common and life-threatening medical emergency requiring careful evaluation from the very first episode and arrival as an attempt to predict and reduce the risk of re-bleeding or death. It has an annual incidence of approximately 67 to 150 per 100,000 with an estimated mortality rates ranging between 6% and 15%, with higher rates of death for those in an unstable hemodynamic state. Objective: The aim of our study was to determine the clinical characteristics and outcome of UGIB patients in TASH adult emergency rooms from January1-December 31, 2019, Addis Ababa, Ethiopia. Methods: We performed descriptive retrospective cross-sectional study on 132 adult UGIB patients in TASH from January1-DecemberV31, 2019. All the UGIB patients seen in the emergency department during the study period were included. A prepared questionnaire was used to collect data on sociodemographic and medical history of the participants. We analyzed the collected data and displayed our results using SPSS and Microsoft Excel. Frequency distribution, 95% confidence Interval, regression and cross tabulation were used for statistical analysis. Results From 132 patients, 97 (73.5%) of them were male (the M:F ratio was 2.8:1). The mean age was 35.99 + 1.324 years. The most common presenting complaints were hematemesis (92.4%) and fatigue (68.2%) followed by melena (67.4%) and loss of appetite (45.5%). Unlike the elderly, participants (>60 years) of our study, the younger participants (<60 years) were more likely to present with hematemesis (92.6% vs 7.4%) and melena (93.3% vs 6.7%). Comorbidities were present in 31.8% of patients. Being a male UGIB patient (p-value= 0.017) was the only significant factor causing the UGIB patients to die in our study participants. A patient transfused with PLT (0.008) and patients given antibiotics (p-value = 0.021) were the protective factors in our study. Conclusions: The most common causes of UGIB were esophageal varices and PUD. Even though endoscopic interventions were mostly successful, diagnostic endoscopy was done for 69 patients and only 30(22.7%) of the patients had therapeutic endoscopy. Efforts are still needed to increase the number of patients receiving endoscopic evaluation and treatment. Mortality was higher in patients <60 years old, with the leading cause of death being hemorrhagic shock. Hence further, studies are needed to see the effects of early scoring, diagnosis and management of patients with hemorrhagic shock and use of appropriate transfusions and prophylaxis antibiotics on outcome of patients with UGIB in the emergency department.