Abstract Background Malnutrition is associated with discontinuing peritoneal dialysis (PD). The prognostic nutritional index (PNI), composed of serum albumin level and total lymphocyte count, has been suggested as a prognostic marker for mortality in patients undergoing PD. However, the relationship between PNI and PD discontinuation has not yet been well addressed. We evaluated the relationship between PNI and PD discontinuation in patients with end-stage kidney disease who initiated PD treatment. Methods This retrospective cohort study included patients who underwent PD at a single academic hospital between 2007 and 2022. We examined the association between PNI (