Objective To explore the relationship between peripheral blood T lymphocyte subsets and prognosis of patients with advanced non-small cell lung cancer (NSCLC) who received treatment with camrelizumab. Methods We retrospectively collected data from 88 patients with advanced NSCLC who underwent camrelizumab treatment. Peripheral blood lymphocyte subsets were collected from patients before and two months after treatment. Kaplan-Meier curves and Cox regression analysis were employed to investigate the relationship between peripheral blood T lymphocyte subsets and PFS and OS. Results Compared with non-responder group, the baseline peripheral blood CD4+/CD8+ ratio was higher (P=0.038), while the CD8+T lymphocyte percentage was lower (P=0.036) in the responder group. Kaplan-Meier curves showed that a high baseline CD4+/CD8+ ratio was associated with long PFS and OS (P=0.001, P=0.023). Multivariate Cox analysis revealed that the baseline CD4+/CD8+ ratio was a significant predictor for PFS and OS. Additionally, a high post-treatment CD4+/CD8+ ratio and high CD4+T lymphocyte percentage were associated with long PFS (P=0.005, P=0.015), whereas a low post-treatment CD8+T lymphocyte percentage was associated with long PFS and OS (P=0.001, P=0.016). Conclusion The peripheral blood CD4+/CD8+ ratio can serve as a predictive factor for survival of patients with NSCLC treated with camrelizumab.