BACKGROUND The results of previous studies that evaluated the association between pretreatment blood platelet-to-lymphocyte ratio (PLR) and clinical outcomes and chemosensitivity in patients with advanced gastric cancer are inconsistent. Therefore, this study was designed to investigate the association between pretreatment blood PLR and clinical outcomes and chemosensitivity in advanced gastric cancer patients. MATERIAL AND METHODS We performed a systematic literature search in PubMed, Web of Science, EMBASE, and the Cochrane Library up to Mar 9, 2021. Hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were pooled for meta-analysis. The quality of the included studies was measured by the Newcastle-Ottawa Quality Assessment Scale. RESULTS We included 17 studies comprising 3499 patients with advanced GC in this meta-analysis. Pooled results demonstrated that high PLR was correlated with poor OS (HR=1.429, 95% CI=1.246-1.639, P<0.001) and DFS (HR=1.47, 95% CI=1.14-1.88, P=0.003) compared with low PLR in patients with advanced GC. Moreover, high PLR was associated with a lower response to chemotherapy in patients with advanced GC (OR=1.395, 95% CI=1.056-1.841, P=0.019). However, there was no significant correlation between PLR and clinicopathological features. CONCLUSIONS This meta-analysis suggests that high PLR is a risk factor for unfavorable OS, DFS, and chemosensitivity in patients with advanced GC.