Objectives: The purpose of this research was to examine the influence of uremia on the mucosa of the upper part of the gastrointestinal system. Subjects and methods: This cross–sectional study included 68 subjects with end–stage chronic kidney disease who are being treated at the Department of Nephrology of the University Hospital Split. The subjects were divided into two groups depending on whether their renal function was replaced by dialysis or not. Demographic characteristics, comorbidities, esophagogastroduodenoscopy findings, and biopsy results were obtained from medical records. Results: Esophagogastroduodenoscopy showed a changed mucosa of the upper part of the digestive system in dialysis patients with a prevalence of 77.94%, while in patients in the non–dialysis group the prevalence was 79.25%. There was no statistically significant difference in the frequency of changes in the mucosa of the digestive system between the examined groups, depending on whether kidney function is replaced by dialysis or not. The most common findings during esophagogastroduodenoscopy in the non–dialysis group were gastritis (53.33%), duodenal erosions/duodenitis (46.67%) and GERD (33.33%). In the dialysis group, the most common findings were gastritis (60.38%), GERD (35.85%) and duodenal erosions/duodenitis (33.96%). There was no statistically significant difference between the examined groups according to macroscopic changes in the mucosa of the upper part of the digestive system (all P>0.05). Conclusion: Pathohistological changes in the mucosa of the upper part of the digestive system are prevalent in patients with terminal (G5) chronic kidney disease and in this study did not depend on the modality of treatment of kidney disease