We investigate if PD-L1 expression and other clinical characteristics predict chemoimmunotherapy (CIT) benefits versus chemotherapy in advanced non-small-cell lung cancer. We performed a meta-analysis of randomized controlled trials of CIT versus chemotherapy identified through electronic searches. In seven randomized controlled trials (n =4170), CIT prolonged progression-free survival over chemotherapy (hazard ratio [HR]: 0.62; 95% CI: 0.58-0.67; p <0.00001). The treatment benefits differed between PD-L1-high (HR: 0.41; 95% CI: 0.34-0.49) and PD-L1 low (HR: 0.63; 95% CI: 0.55-0.72; interaction-p = 0.00002) and PD-L1-high and PD-L1-negative (HR: 0.72; 95% CI: 0.65-0.80; interaction-p <0.00001). Similar benefits were observed regardless of gender, EGFR/ALK status and histological subtype. PD-L1 status is predictive of CIT benefit and may assist patient selection and design of future trials.