The concept of "trifecta" since its first description has become a convenient tool to assess perioperative outcomes after partial nephrectomy (PN) for renal cell carcinoma (RCC). Emerging studies have demonstrated a positive association between trifecta achievement and improved survival and functional outcomes after PN. Recently, preoperative C-reactive protein (CRP) has been advocated as a useful tool to predict oncological outcome and renal functional decline. Herein we sought to integrate preoperative CRP into trifecta criteria to increase its prognostic capability. We examined our prospective database of patients with localized RCC (cT1-T3) who underwent PN. Trifecta was defined as negative surgical margins, no major postoperative complications of Clavien Dindo grade ≥3, and perioperative eGFR decrease of <30%. The primary outcome was all-cause mortality (ACM), and the secondary outcome was de novo eGFR of <45mL/min/1.73m2 (CKD-S3b). We performed multivariate analysis (MVA) using Cox regression to analyze the association between preoperative CRP and trifecta for ACM. Cut-point analysis using the concordance probability method identified CRP thresholds for low (LCRP) and high (HCRP) levels. Kaplan-Meier analysis (KMA) evaluated the overall survival (OS) and CKD-S3b progression-free survival, stratifying patients based on trifecta achievement and preoperative CRP levels. We proposed a new trifecta stratification based on the survival distributions. The Aikaike Information Criterion (AIC) was used to assess the performance of the proposed classification. 456 patients over a 34-months follow-up period were analyzed, with 316 (67.9%) achieving trifecta. MVA revealed CRP (HR;1.01,;p=0.007) as associated with higher ACM risk.;Trifecta was associated with reduced risk (HR 0.38,;p=0.004). Cut-point analysis established HCRP as ≥5 mg/L. KMA demonstrated trends in the trifecta group with 5-year OS rates of 95.6% for LCRP and 90.1% for HCRP (p=0.13). In the non-trifecta group, rates were 91.3% for LCRP and 59.7% for HCRP (p<0.001). 5-year CKD-S3b-free survival rates in the trifecta group were 83.9% (LCRP) and 80.9% (HCRP,;p=0.80), whereas rates in the non-trifecta group were 91.5% vs. 63.2%, respectively (p<0.001). Proposed risk stratification system is low (trifecta+LCRP), intermediate (trifecta+HCRP; no-trifecta+LCRP), and high (no-trifecta+HCRP). Proposed stratification;demonstrated lower AIC, translating to superior performance, in predicting ACM and CKD-S3b compared to trifecta (369.921 vs. 381.272; 661.783 vs.671.321, respectively). Our findings suggest that non-trifecta patients with low preoperative CRP demonstrated similar outcomes to patients who achieved trifecta. Together these findings suggest that preoperative CRP could identify a subgroup of patients at risk for adverse outcomes. Further investigation is warranted. [ABSTRACT FROM AUTHOR]