The prevalence of Helicobacter pylori was determined using an ELISA technique for IgG antibodies to H. pylori in 76 patients with end-stage renal failure who were receiving regular haemodialysis and 202 patients with functioning renal transplants. Twenty-seven (34%) of the haemodialysis group and 58 (29%) of the transplant group were positive for H. pylori IgG antibodies, and the prevalence did not differ significantly from that in 247 age-matched healthy controls. In the haemodialysis group, patients positive for H. pylori were older, median age 60 years (range 22–73), compared to those patients without H. pylori antibodies, median age 52 years (range 22–75), p < 0.05, more suffered from dyspeptic symptoms, 35 vs. 10% (p < 0.01), yet fewer had been prescribed aluminium-containing antacids, 38 vs. 78% (p < 0.01). In the transplanted group, those positive for H. pylori were more symptomatic for dyspepsia, 30 vs. 11% (p < 0.01), and had lower serum creatinine values, 136 ± 10 μmol/l (mean ± SEM) vs. 172 ± 12 μmol/l (p < 0.05), compared to those without H. pylori antibodies. Almost all the transplant patients with H. pylori antibodies were taking steroids (98%) compared to 84% of those without antibodies (p < 0.05). The prevalence of antibodies to H. pylori in this study was increased in symptomatic dyspeptic subjects and reduced in those patients prescribed aluminium-containing phosphate binders.