OBJECTIVE: The purpose of this prospective study is to determine the prevalence of upper gastrointestinal (GI) abnormalities and Helicobacter pylori (H. pylori) infection among stable chronic hemodialysis (HD) patients. METHODS: The study was carried out at King Fahd Hospital of the University, Al-Khobar, Kingdom of Saudi Arabia during the period January 1996 to June 1997. Fifty-four chronic HD patients underwent upper GI endoscopy. Endoscopic changes were described and multiple antral gastric biopsies were taken for histological examination and detection of H. pylori infection. Gastric biopsy findings were compared to findings in 60 consecutive patients with normal renal function undergoing endoscopy for assessment of dyspepsia. RESULTS: Fifty-four stable chronic HD patients (32 men, mean age 42.4 +/- 18 years) underwent upper GI endoscopy and multiple antral gastric biopsies for histological examination and H. pylori detection. The endoscopic findings were abnormal in 49 (90.7%) patients. Chronic gastritis was seen in 20 (37%) patients, acute gastritis was seen in 13 (20.1%) patients, duodenal ulcer was seen in 6 (11.1%) patients, duodenitis with or without erosions was seen in 5 (9.3%) patients, gastroduodenitis was seen in 3 (5.56%) patients, and gastroesophageal reflux disease was seen in 2 (3.7%) patients. Histological examination of multiple antral gastric biopsies documented chronic active gastritis in 28 (51.9%) patients. Helicobacter pylori were present in 34(63%) patients. Helicobacter pylori were detected in the majority (85.7%) of patients with the histological diagnosis of chronic active gastritis. Patients harboring H. pylori were significantly older than negative patients (52 +/- 16.1 versus 33.9 +/- 17.3 years, p<0.018). In a group of 60 patients with normal renal function undergoing endoscopy for assessment of dyspeptic symptoms during the same period, chronic active gastritis was found in 40 (66.7%) patients and H. pylori was detected in 38 (63.3%) patients. CONCLUSION: Upper GI abnormalities are common among HD patients even in the absence of symptoms. Biopsy proven chronic active gastritis is the most common histological diagnosis among these patients and is highly associated with H. pylori infection. Prevalence of H.pylori infection in HD patients is similar to those with normal renal function undergoing endoscopy for dyspepsia. Helicobacter pylori infected HD patients tend to be older than patients without H.pylori infection.