Systemic inflammation and nutritional status are increasingly recognized as prognostic determinants in glioblastoma (GBM). The CRP–albumin–lymphocyte (CALLY) index integrates inflammatory and immune-nutritional components, yet its prognostic value in GBM remains unclear.

This study compared the prognostic performance of CALLY with other inflammation-based indices, including NLR, SII, SIRI, PIV, and NLPR.

Ninety-two patients with histologically confirmed GBM treated with maximal safe resection followed by standard concurrent radiotherapy and temozolomide (Stupp protocol) were retrospectively analyzed (2019–2025). Baseline hematologic indices were calculated from pre-treatment blood tests. Survival outcomes were assessed using Kaplan–Meier and Cox regression analyses. Prognostic discrimination was quantified with time-dependent ROC curves and bootstrap-corrected AUCs at 6- and 12-month horizons.

Median overall survival (OS) and progression-free survival (PFS) were 14 months and 6 months, respectively. A CALLY cut-off of 1.92 best discriminated outcomes: median OS 21 months vs. 10 months and PFS 14 months vs. 4 months (p < 0.001). CALLY achieved the highest AUCs for 12-month PFS (0.915) and OS (0.891), maintaining significance after internal validation. In multivariable analysis, low CALLY independently predicted poorer OS (HR = 3.83; p = 0.002) and PFS (HR = 7.69; p < 0.001). SIRI and PIV ranked second and third in discriminative performance.

In this single-centre retrospective cohort, lower baseline CALLY scores were associated with inferior survival outcomes in patients with GBM. These findings suggest that CALLY may represent a potentially useful inflammation-based prognostic marker. However, given the exploratory design and limited sample size, prospective multicentre studies are required to validate these results before clinical implementation.