The aim of this study is to determine the effects of the values-based mathematics teaching activities on mathematics achievement and mathematics attitudes of 8th grade students in Türkiye. For the study, a control group pretest-posttest quasi-experimental design was used. A total of 59 students (experimental group 29; control group 30) from a middle school participated in this study. In the study, the values-based mathematics activities prepared by the researchers were conducted to the experimental group. The Mathematics Attitude Scale (MAS) and the Mathematics Achievement Test (MAT) were administered to the experimental and control groups before and after the experimental process. In addition, at the end of the experiment process, a semi-structured interview was conducted with 6 students in the experimental group. The results revealed that the values-based mathematics teaching activities did not create a significant difference in the mathematics achievement of 8th grade students, but had a positive effect on their mathematics attitudes.