OBJECTIVE: To validate an association between new inflammation and frequent peritoneal dialysis-associated peritonitis (PDAP). MATERIALS AND METHODS: In China, retrospective clinical data were collected on 208 patients who received continuous ambulatory peritoneal dialysis (CAPD) between 2010 and 2021. The patients were divided into two groups: non-frequent PDAP (the interval between two peritonitis episodes of more than one year) and frequent PDAP (the interval between two peritonitis episodes of less than one year). Patients with their first episode of peritonitis had their age, gender, history of hypertension, diabetic disease, underlying renal disease, bacterial infection, and laboratory data collected. The outcomes of bacterial dispersion, systemic immune-inflammation index (SII), high-density lipoprotein cholesterol (HDL-C), C-reactive protein (CRP), and risk variables associated with frequent PDAP were analyzed. RESULTS: There are differences between the two groups in dialysis time (p = 0.006), hypertensive nephropathy (p = 0.038), staphylococcus (p = 0.035), white blood cells (p = 0.001), neutrophil (p < 0.01), lymphocyte (p < 0.01), platelet(p = 0.01), SII(p < 0.01), CRP/HDL-C (p = 0.002), CRP (p < 0.001), serum creatinine (p = 0.007), blood urea nitrogen (p = 0.05), serum magnesium (0.03), serum potassium (p = 0.007), and dialysate polymorphonuclear cells (p = 0.004). Multifactorial logistic regression analysis found that SII (p < 0.001), CRP/HDL-C (p = 0.041), and Diabetes mellitus (p = 0.027) were independent risk factors for frequent PDAP. The ROC curve analysis revealed that combining SII with CRP/HDL-C resulted in the largest AUC area (AUC = 0.814). CONCLUSIONS: Our findings offer clinical proof of the combination of SII and CRP/HDL-C in patients with frequent PDAP.