We endoscoped 322 of 422 patients with end-stage renal failure undergoing maintenance dialysis treatment to determine the prevalence of erosive prepyloric changes (EPC) in uraemia. EPC grade 1 was found in 79 patients (25%), grade 2 in 16 (5%), and grade 3 in 43 (13%). EPC grades 2 and 3 were commoner among uraemic patients than among non-uraemic patients presenting for gastroduodenoscopy (13 of 198 = 6%; p < 0.001). Patients with EPC grades 2 and 3 were older, had been receiving dialysis longer, and were more likely to be receiving haemodialysis rather than peritoneal dialysis when compared with patients without EPC. Histologic gastritis of the body and antrum was less common among patients with EPC grades 2 and 3 than among patients without EPC. The prevalence of Campylobacter-like organisms was similar in patients with and without EPC.