the purpose of the research is to examine if integrating cooperative learning into vocabulary learning helps to increase word recognition of students in an elementary school in iran. it tries to investigate whether cooperative learning approach enables students to improve their language learning. this research used stad (students team achievement division) as a cooperative model in this study. two classes of the fifth grade students in an elementary school participated in the study. the students in the experimental group received the treatment, which was teaching vocabulary through cooperative learning approach. in this study quantitative data was analyzed by using mean, t-test and standard deviation to find out whether there were significant differences in participants’ word recognition before and after the treatment. the results showed that there was significant improvement on word recognition of the participants in the experimental group. based on the conclusions of study, integrating of cooperative learning into the elementary school english instruction is recommended. pedagogical implications and suggestions for future studies were provided.