This study evaluated the prognostic significance of the C-reactive protein–albumin–lymphocyte (CALLY) index and systemic immune-inflammation (SII) index in predicting postoperative outcomes in patients with esophageal squamous cell carcinoma (ESCC). A retrospective analysis was performed on clinical data from 102 patients with ESCC who underwent surgical resection at Western Theater General Hospital of China between January 2020 and July 2023. The associations between preoperative CALLY and SII indices and relapse-free survival (RFS) and overall survival (OS) were examined. Survival curves were generated using the Kaplan–Meier method, and prognostic factors were identified using Cox proportional hazards regression analysis. Patients with a high CALLY index had significantly longer RFS (HR=0.30, 95% CI: 0.13-0.71), and those with a low SII index also had significantly longer RFS (HR=2.23, 95% CI: 1.12-4.41). Similarly, patients with a high CALLY index had significantly longer OS (HR=0.27, 95% CI: 0.13-0.55), and those with a low SII index had significantly longer OS (HR=2.27, 95% CI: 1.09-4.71). When patients were stratified into four groups, the low-CALLY–high-SII group showed significantly shorter RFS than the high-CALLY–low-SII group (HR=0.26, 95% CI: 0.11-0.61; p=0.013), and OS was also significantly worse in the low-CALLY–high-SII group (HR=0.22, 95% CI: 0.09-0.54; p=0.016). Univariate Cox regression analysis identified both CALLY and SII as significant prognostic factors. In multivariate analysis, the CALLY index and N stage were independently associated with RFS, whereas only tumor size remained independently associated with OS. The combined assessment of preoperative CALLY and SII indices may be useful for prognostic stratification in patients with ESCC undergoing upfront surgical resection. It may help identify high-risk patient subgroups with distinct survival outcomes, thereby providing a potential rationale for stratifying postoperative surveillance and tailoring individualized adjuvant strategies, although validation in larger prospective cohorts is warranted.