Chronic renal failure was suggested as a protective factor against Helicobacter pylori infection in adults. Therefore, this study was designed to ascertain the prevalence of H. Pylori infection, histopathology and endoscopic finding among children with chronic renal failure. This was a retrospective descriptive / analytic cross – sectional study conducted from 1997 to 2005 in Ali asghar children hospital. 32 children (14 male, 18 female) aged 1-16 years with chronic renal failure (GFR< 70 ml/min), who were candidates for renal transplantation, underwent routine upper endoscopy. 107 children (54 male , 53 female) with normal renal function (GFR >90 ml/min) in whom endoscopy were done due to abdominal pain , FTT , GI bleeding , malabsorption , or nausea and vomiting were assigned as control. Sample selection method was convenient for cases and simple random from file numbers for control group. Two specimens of biopsy were taken from stomach and duodenum, H pylori was detected on histopathology by Geimssa staining. The outcome was H. pylori positive, gastritis in pathology and erythema, erosion or ulcer on endoscopy. Chi square and Table 2x2 was used to estimate the prevalence and Odd ratio. P <0.05 was considered significant. Control group was twice more symptomatic than case group; however, this difference was not significant. Nausea and vomiting in controls were 4.7%, in cases they were 15.6%; abdominal pain in controls were 31.8 % , in cases were 6.3% ( P= 0.003) ; gastrointestinal bleeding in controls were 8.2% and in cases were 6.3% . Prevalence of H pylori was lower in patients with CRF but it was not significant. Children with CRF were five times as likely to develop duodenitis diagnosed by pathology compare to control group. (P= 0.002) 19 out of 32 children with CRF were 4 years (+/- 2) in average on hemodialysis the prevalence of H pylori , endoscopic and pathologic findings were similar in those on dialysis and CRF children. Conclusion: Although the prevalence of H pylori in children with CRF was lower; the rate of duodenitis accompanied with gastritis was significantly higher in this group.