As a result of rapid development in technology, utilizing materials in education has become important. To date, researchers have often explored the effects of using educational materials in mathematics instruction on academic achievement. The purpose of this study was to combine the empirical evidence regarding the effectiveness of educational materials in mathematics. For this aim, a meta-analysis method was used in the current research. In line with the aim of the research, 54 experimental studies published between years of 2005 and 2016 were included in the meta-analysis and 58 effect sizes were calculated from these studies. The results of the meta-analysis showed that using materials in mathematics has a positive and high influence on achievement. According to analysis of mediator variables that are related to instructional characteristics, significant differences are found in the variables of mathematics topic, type of material, and application time. However, teaching with materials in mathematics did not seem to differ in effectiveness from teaching without materials, in terms of methodological characteristics of the studies.