Computed tomographic (CT) peritoneography has been widely used as reference standard to evaluate continuous ambulatory peritoneal dialysis-related complications. However, given the varying CT peritoneography approaches used across different institutions, there is no standard value for non-ionic iodinated contrast media (ICM) concentration. Few studies have currently investigated whether non-ionic iodinated contrast media (non-ionic ICM) affects peritoneal function or residual renal function (RRF). This study aimed to determine whether different non-ionic ICM concentrations affect peritoneum and RRF and attempted to evaluate CT peritoneography images to identify the optimal non-ionic ICM concentrations in animals. To this end, 25 male Sprague-Dawley rats were used to establish uraemic models, after which they were injected with a 40-mL mixture of peritoneal dialysate and iohexol at varying concentrations prior to CT peritoneography. Thereafter, two experienced radiologists blinded to the rat groupings evaluated image quality, peritoneal morphology and thickness were assessed using hematoxylin and eosin and Masson staining, and RRF was evaluated using serum creatinine levels hematoxylin and eosin staining of pathological kidney sections. Briefly, non-ionic ICM had negligible effects on the peritoneum and RRF. Our results suggest that a mixture containing 50 mL (350 mgI/mL) iohexol/2 L peritoneal dialysate can be used as reference in rats.© 2020 Wiley Periodicals, Inc.