BACKGROUND: The incidence of upper gastrointestinal bleeding has decreased in the general population but has increased in geriatric patients worldwide. The aim of this study was to evaluate the clinical characteristics and outcomes of geriatric patients (aged 65 or older) with upper gastrointestinal bleeding and to compare them with non-geriatric patients (less than 65 years old). METHODS: We conducted a retrospective study of 288 patients with upper gastrointestinal bleeding from January 2007 to August 2010. We compared the clinical characteristics and outcomes of geriatric patients (n=148, 51.4%) with those of non-geriatric patients (n=140, 48.6%). RESULTS: Cardiovascular disease, hypertension, and cerebrovascular accidents were more prevalent in the geriatric group, compared with those in the non-geriatric group (p<0.05). Vital signs were more unstable in the geriatric group than those in the non-geriatric group (p<0.05). The geriatric group had taken more ulcerogenic drugs than those in the non-geriatric group (p<0.05). The most common cause of upper gastrointestinal bleeding was peptic ulcer (72.3%) in the geriatric group, whereas it was variceal bleeding (41.4%) in the non-geriatric group. Treatment methods, transfusion volume, operation rate, and mortality were not different between the two groups. The length of hospital stay and length of intensive care unit (ICU) stay were significantly longer in geriatric patients than those in the non-geriatric group (p<0.05). CONCLUSION: Geriatric patients with upper gastrointestinal bleeding had longer ICU and hospital stays than those of non-geriatric patients. Important emerging etiologies such as ulcerogenic drugs and associated chronic illness should be monitored and treated early in these patients.