BackgroundThe C-reactive protein (CRP)–albumin–lymphocyte (CALLY) index is a novel immuno-nutritional biomarker based on the levels of CRP, serum albumin, and lymphocyte count. This study examined the prognostic value of the CALLY index in patients with colorectal cancer undergoing curative surgery. MethodsBetween 2010 and 2017, 578 patients with stage II-III colorectal cancer who underwent curative resection were enrolled. The CALLY index was defined as (albumin × lymphocyte)/(CRP × 104). We investigated the association of the CALLY index with disease-free survival (DFS) and overall survival (OS). ResultsThe cutoff value of the CALLY index was determined to be 2. Of the 578 patients, 175 (30%) had a preoperative CALLY index <2. In multivariate analysis, the pre-operative carcinoembryonic antigen (CEA) level (p = 0.003), cell differentiation (p = 0.045), venous invasion (p = 0.036), Tumor-Node-Metastasis stage (p < 0.001), and CALLY index score <2 (p = 0.006) were independent predictors of DFS. Meanwhile, preoperative carbohydrate antigen (CA)19-9 levels (p = 0.019), lymphatic invasion (p = 0.018), preoperative platelet (p = 0.037), and CALLY index score <2 (p = 0.007) were independent predictors of OS. ConclusionThe CALLY index may be an independent prognostic biomarker for long-term outcomes in patients with colorectal cancer.