Upper gastrointestinal bleeding (UGIB) is a medical emergency. There is no precise information of its prevalence and prognosis in patients. The aim of present study was to investigate the prognostic factors of UGIB in patients. In this prospective observational study 75 patients with UGIB referred to Hospital. Demographic and clinical data of them were recorded and analyzed. Mortality rate in first hospitalization was 16% and in one-month follow up was 4%. There was no significant association between age and gender with duration of hospitalization and one-month prognosis (p>0.05). Mortality was associated with acute abdomen and orthostatic hypotension I admission time, peptic ulcer in endoscopic evaluation, active bleeding, ICU admission and need to second endoscopy (p<0.05). Erosive gastritis, need to emergent surgery and use of NSAIDs significant increase of mortality rate (p<0.05). It seems admission time signs and symptoms, hemodynamic and coagulation status, endoscopic results and need to re-endoscopic evaluation are more prognostic factors in patients with UGIB.