To assess the characteristics of patients with upper gastrointestinal system (GIS) bleeding. Materials and methods: 195 patients with upper GIS bleeding admitted to our clinic between 2000- 2005 were retrospectively evaluated. Age, sex, complaints, history of medication, history of bleeding, laboratory findings, endoscopic findings, management, need for transfusion, hospitalization duration and mortality rates were assessed. Results: 151 (77.4%) patients were men and 44 (22.6%) were women (p<0.05). Mean age was 59.2 years and GIS bleeding was most common in the 7th and 8th decades. Melena (37.9%), hematemesis (8.7%), and hematemesis and melena (53.3%) were the complaints at admission. Patients were using nonsteroidal antiinflammatory drugs (NSAID) (19%), aspirin (A) (18.5%), oral anticoagulant drugs (OAC), steroids or combination therapies (11.3%). The mean hemoglobin, hematocrit, urea and creatinine levels were 8.8 g/dl, 27.0%, 76.9 mg/dl, and 1.1 mg/dl, respectively, at admission. Peptic ulcer (29.3%) and esophageal varices (17.9%) were the most common findings at upper GIS endoscopy. Endoscopy could not be performed in 56 patients (28.7%). Only medical treatment was administered to 182 patients, band ligation was performed in 8 patients, sclerotherapy was performed in 3 patients and surgery was needed in 1 patient. The mean transfusion need was 4.6 units and the mean duration of hospitalization was 7.8 days. 20 patients died during follow-up and 9 of these were due to bleeding. Conclusion: To decrease the mortality, accompanying diseases must be managed effectively and bleeding control provided. Patients who use A/NSAIDs, especially for controlling pain and inflammation, should be treated with protective drugs, and if NSAID treatment is needed, COX-2 should selectively be preferred.