Abstract. The cytotoxic T-lymphocyte antigen 4 (CTLA-4) polymorphic loci -318 cytosine/thymine (-318C/T) has been previously implicated in malignant tumor susceptibility. However, there were no precise conclusions about the correlation, the results from published studies were inconclusive. The aim of the current meta-analysis was to investigate the associations between CTLA-4 -318C/T polymorphisms and risk of malignant tumors in Asian population. We conducted a search in PubMed, Embase, the Chinese Journals Full-Text Database, Chinese Biomedical Database, and the Wanfang database. All studies were published up to September 30, 2015. Two reviewers analysed the data independently. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association. In total, 20 case-controlled studies with 3,539 cases and 4,690 controls were included in the final meta-analysis. The overall estimation demonstrated a significant association between CTLA-4 -