Background <p>Obesity is a growing public health concern and may influence outcomes in end-stage kidney disease (ESKD) patients undergoing peritoneal dialysis (PD). However, its impact on in-hospital complications, mortality, and healthcare utilization in this population remains unclear. This study aimed to assess the association between obesity and hospitalization-related outcomes in PD patients.</p> Methods <p>This study was conducted using the National Inpatient Sample to identify hospitalized ESKD patients receiving PD from the year 2003 to 2018. The in-hospital treatments, outcomes, and resource utilization were compared between obese and non-obese patients, adjusting for age, sex, race, year of hospitalization, and comorbidities.</p> Results <p>A total of 100,523 hospitalized ESKD patients receiving PD were included in the analysis. Of these, 9890 (9.8%) had obesity diagnosis. In the adjusted analysis, obese patients had a higher need for procedures for PD catheter adjustment or removal (OR 1.29; 95% CI 1.16–1.43), hemodialysis (OR 1.28; 95% CI 1.19–1.38), and mechanical ventilation (OR 1.29; 95% CI 1.16–1.44), compared to non-obese patients. Obesity was significantly associated with higher risk of PD peritonitis (OR 1.12; 95% CI 1.06–1.19) and fluid overload (OR 1.34; 95% CI 1.23–1.45) but lower in-hospital mortality (OR 0.84; 95% CI 0.73–0.96). There was no significant difference in length of hospital stay and hospitalization cost between obese and non-obese patients.</p> Conclusion <p>Among hospitalized PD patients, obesity is associated with higher PD-related complications and increased need for interventions but is paradoxically linked to lower in-hospital mortality. These findings provide new insights into the obesity paradox in PD and highlight the need for tailored management strategies to mitigate obesity-related risks in hospitalized PD patients.</p>