This study aims to perform a meta-analysis of quantitative studies on the effect of middlthie school students' attitudes towards mathematics on academic achievement. The study was conducted with a meta-analysis method, systematically examining the quantitative findings. In this context, postgraduate theses published on the attitude of middle school students to mathematics lessons were scanned in the database of the National Thesis Center (YÖKTEZ), as a result, 56 research findings out of 49 studies that met the criteria were included in the study. In the study, the type of publication, gender, class level, and duration of application was determined as moderator variables. The data were analyzed by using the CMA program. At the end of the research, it was concluded that students' mathematics attitude had a statistically significant and moderate effect (Hedges's g = 0.728) compared to the random-effects model. Additionally, it was observed that the effect sizes reported in the studies included in the meta-analysis showed a heterogeneous distribution (Qmodel = 409.396; df (Q) = 55; p = .000). The reasons for the heterogeneous distribution of the effect sizes reported in the studies were tested with subgroup analyzes (Analog ANOVA, Meta-Regression). Among the tested variables, class level (Qb = 11.293; p = 0.010) and the duration of administration (Qb = 10.159; p = 0.017) were found to be statistically significant. In this study, it was seen that a positive attitude towards mathematics is beneficial and effective for the academic success of the students. Additionally, at the end of the study, it was seen that there was a significant, positive and moderate relation between the positive attitude towards mathematics and the mathematics achievement.

Mathematics attitude, middle school students, meta-analysis, effect size.