Student-Team Achievement Division (STAD) is one of the cooperative learning structures that make use of rewards or incentives to promote team collaboration. This study finds out the effects of STAD on the academic performance of Grade 8 students in physics in a public school. There were two groups in this study: the experimental group and the control group. The exp erimental group utilized STAD while the control group employed the Inquiry-Based Approach. Each group has thirty-two (32) respondents. The instrument of the study was a researcher-made achievement test. This study lasted for six (6) weeks which covers the entire first quarter of Science 8. This research made use of the true experimental design. The comparability of the experiment was tested using t-test. The result showed that there is no significant difference in the posttest mean scores between the experimental and control groups. However, students exposed to STAD posted higher gain scores compared to the students exposed to the Inquiry-Based Approach. Based on the findings of the study, the use of STAD has improved the students’ academic performance through cooperation with their groupmates.