We analyzed the levels of 799 EV-miRNAs in the pretreatment plasma of 88 advanced NSCLC patients who received anti-PD-1 therapy as single agent...abundance of EV-miR-625-5p was found to be correlated with PD-L1 expression and significantly associated to OR by RECIST (p = 0.0366) and OS (p = 0.0031)....Considering tumor size change at best response, the miR-625-5p Low/PD-L1 ≥ 50% group showed a mean reduction in tumor size of 34.45% (median 33.5%)....In the OS analysis, the miR-625-5p Low/PD-L1 ≥ 50% group showed the longest median survival (27.0 months)...in the PFS analysis, the miR-625-5p Low/PD-L1 ≥ 50% group showed the longest median survival (24.0 months)...this study suggests that EVs-miR-625-5p might represent a novel biomarker to stratify patients affected by NSCLC treated with ICIs (nivolumab and pembrolizumab as monotherapy), in particular those with PD-L1 expression ≥50%.