Case-control study comparing 81 patients with chronic renal failure (CRF) with 58 patients without renal disease who were evaluated by endoscopy of upper and/or lower gastrointestinal tract (GIT) for gastrointestinal bleeding or dyspepsia. The success of endoscopic examinations was the same in both groups. Patients with CRF more often underwent endoscopic examination because of gastrointestinal bleeding and they presented more often by hematochezia. Patients with CRF were more often found to have hemorrhagic gastropathy or duodenopathy and angiodysplasia of upper and lower GIT. However, duodenal ulcer was significantly more common in the control group without renal disease. Incidence of Helicobacter Pylori infection was low in both groups.