The aim of this study was to examine the effects of self-regulated Jigsaw IV on mathematics achievement, self-efficacy beliefs, and mathematics anxiety among 5th-grade students. The pretest and post-test non-equivalent control group design was utilized in the study. The participants consisted of 40 fifth graders, half of them were assigned to the experimental group, and the other half were assigned to the control group. A traditional instruction was used in the control group whereas the experimental group received the instruction based on the self-regulated Jigsaw IV technique. The intervention lasted for six weeks. An academic achievement test, a mathematics anxiety-apprehension survey, and a self-efficacy belief scale were administered as the pretest and post-test. Based on the findings, the self-regulated Jigsaw IV technique was more effective in enhancing students' math achievement and self-efficacy beliefs compared to the conventional instruction. Additionally, the technique was found to be more effective in reducing mathematics anxiety. Therefore, the Jigsaw IV integrated with self-regulated strategies is recommended to be used in the learning process. [This paper was published in: "EJER Congress 2024 International Eurasian Educational Research Congress Conference Proceedings," edited by Senel Poyrazli, Ani Publishing, 2024, pp. 166-171.]