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-mu-mol/l (mean +/- SEM) vs. 172 +/-12-mu-mol/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.