Abstarct: This quasi-experimental study investigated the effect of cooperative games on enhancing student participation in primary school English as a Foreign Language (EFL) classes, addressing the persistent challenge of low learner engagement in teacher-centered classrooms. The primary objective was to determine whether cooperative games have a statistically significant positive effect on EFL students' participation compared to traditional instruction. A total of 64 primary school students (grades 3-5) participated in a pretest-posttest control group design. The experimental group (n=32) received eight weeks of instruction through structured cooperative games characterized by positive interdependence, individual accountability, and English communication, while the control group (n=32) received traditional teacher-centered instruction covering identical language content. Student participation was measured using the Student Participation Observation Scale (SPOS) and the Student Participation Self-Assessment Scale (SPSAS). The findings revealed that cooperative games had a statistically significant positive effect on student participation with a large effect size (partial η² = 0.362). The experimental group demonstrated significant improvements in both behavioral participation (SPOS) and self-perceived willingness to participate (SPSAS), while the control group showed no significant improvement. Paired samples t-tests confirmed substantial gains for the experimental group (d=2.61) versus negligible gains for the control group (d=0.32). These findings contribute empirical evidence supporting cooperative games as an effective pedagogical intervention for enhancing student participation in primary EFL contexts, with practical implications for teachers, curriculum developers, and teacher education programs seeking to create more engaging, learner-centered language classrooms.