Abstract: Objective  To investigate the factors influencing peritoneal residual volume (PRV) and its impact on dialysis efficiency in patients undergoing peritoneal dialysis.  Methods Data on demographics and clinical biochemistry were collected from patients receiving maintenance peritoneal dialysis between January 2019 and December 2023 at the Second Affiliated Hospital of Harbin Medical University. The position of the peritoneal dialysis catheter tip was recorded via abdominal supine radiography or pelvic CT. PRV after dialysis was calculated using the Twardowski method based on creatinine levels in the dialysate at 0 and 4 hours. Patients were divided into high-PRV and low-PRV groups, and factors influencing PRV were analyzed using t-tests. The impact of PRV on dialysis efficiency was also assessed. Results  A total of 112 patients were included, with 72(64.3%) undergoing ultrasound-guided percutaneous catheter placement and 40(35.7%) undergoing surgical placement. There was no significant difference in catheter tip position between the two methods (r =0.665, P =0.717). PRV was associated with catheter tip position (t=-8.502,P=0.001) but not with abdominal surgery history, BMI, abdominal circumference, or surgical method. Compared to the high-PRV group (n =39), the low-PRV group (n =73) had better post-dialysis blood pressure control (t =-5.019, P=0.001), lower NT-proBNP (t=-3.537, P=0.001), and higher dialysis Kt/V (t = 4.430, P=0.001), Ccr (t =2.786, P=0.001), and prealbumin levels (t=2.057, P=0.031).  Conclusions The position of the peritoneal dialysis catheter tip in the abdomen affects PRV, and high PRV reduces peritoneal dialysis efficiency.