This study aimed to explore the association between inflammation-based prognostic markers and outcomes in non-small cell lung cancer (NSCLC) patients undergoing therapy with immune checkpoint inhibitors (ICIs). We conducted a comprehensive search of the Embase, PubMed, and Cochrane databases for studies that reported on the impact of inflammation-based prognostic factors, such as C-reactive protein (CRP), on the prognosis of NSCLC patients treated with ICIs. The primary outcomes of interest were overall survival (OS) and progression-free survival (PFS). Statistical analyses were performed using Stata 14 software, with assessments of publication bias and heterogeneity conducted as necessary. Our meta-analysis included 27 studies encompassing 5,174 patients, evaluating factors such as CRP, the modified Glasgow Prognostic Score (mGPS), and the CRP-albumin ratio (CAR). The analysis revealed that elevated levels of CRP were significantly correlated with both reduced PFS (I = 0%, P = 0.72; HR = 1.50, 95%CI: 1.33-1.67, P < 0.01) and shorter OS (I = 0%, P = 0.55; HR = 1.90, 95%CI: 1.50-2.30, P < 0.01). Similarly, elevated levels of mGPS values were associated with worse PFS (I = 0%, P = 0.75; HR = 1.28, 95%CI: 1.10-1.46, P < 0.05) and OS (I = 0%, P = 0.94; HR = 1.56, 95%CI: 1.31-1.81, P < 0.05). However, the relationship between elevated levels of CAR and worse outcomes for PFS (I = 59.6%, P = 0.94; HR = 1.42, 95%CI: 0.74-2.11, P > 0.05) and OS (I = 45.3%, P = 0.16; HR = 1.41, 95%CI: 0.70-2.13, P > 0.05) was not statistically significant. Our findings suggest that CRP and mGPS may serve as potential prognostic markers in NSCLC patients receiving immunotherapy. Nonetheless, further research with more homogeneous study populations is necessary to valid these observations.