Background Although the immune checkpoint inhibitors (ICIs) became a vital part of cancer care, many patients do not respond to treatment, indicating need for biomarkers. The Pan-Immune-Inflammation Value (PIV) is a recently developed peripheral blood count-based biomarker. Herein, we evaluated a PIV-based candidate scoring system as a prognostic biomarker in ICI-treated patients. Methods A total of 120 advanced cancer patients treated with anti-PD-1 or anti-PD-L1 inhibitors for any cancer type were included in this study. The PILE scoring system incorporating the PIV (< median vs. >= median), lactate dehydrogenase levels (normal vs. > normal) and Eastern Cooperative Oncology Group performance status (0 vs. >= 1) was constructed from the multivariate analyses and used for stratification. The association between overall survival (OS), progression-free survival and PILE risk category was evaluated with multivariate analysis. Results The median follow-up was 9.62 months and the median OS of all cohort were 12.42 +/- 2.75 months. Patients with higher PIV had significantly decreased OS (7.75 +/- 1.64 vs. 18.63 +/- 4.26 months, p = 0.037). The patients in the PILE high-risk group (PILE score 2-3) had decreased OS (18.63 +/- 4.02 vs. 5.09 +/- 1.23 months, HR: 2.317, 95% CI: 1.450-3.700, p < 0.001) and PFS (7.69 +/- 1.30 vs. 2.69 +/- 0.65 months, HR: 1.931, 95% CI: 1.263-2.954, p = 0.002) compared to PILE low-risk group (PILE score 0-1). The Harrell C-Index values were 0.65 and 0.61 for OS and PFS prediction, respectively. Conclusion In this study, we demonstrated a decreased overall survival in ICI-treated patients with a higher PILE score. If prospective studies validate our results, PILE score could be a biomarker for immunotherapy.