In this research, the effects of using game in mathematics teaching process on academic achievement in Turkey were examined by metaanalysis method. For this purpose, the average effect size value and the average effect size values of the moderator variables (education level, the field of education, game type, implementation period and sample size) were calculated. MetaWin and Comprehensive MetaAnalysis (CMA) statistical programs were used for the analysis. Based on the inclusion criteria, 31 effect size values for 26 studies were calculated. Hedges's g coefficient was used when the effect sizes were calculated and the confidence level was accepted as 95%. The average effect size value was 0.792 with 0.077 standard error which was calculated by random-effects model. As a result, the effects of using game on academic achievement is medium and positive in mathematics teaching process.