Graphic organizers have been employed to facilitate second language learners' vocabulary knowledge development; however, the examination of the effects of these graphic organizer options on learners' collocation knowledge development has remained unexplored. This research investigated the effects of using teacher-generated, individually-generated, and cooperatively generated graphic organizers on Iranian English language learners' collocation knowledge. The present study examined these effects by studying 80 intermediate second language learners who were selected based on convenience sampling. The participants were assigned to four groups randomly. The collocations were provided on the board in the control group, and explanations were provided orally. In the teacher graphic organizer group, the teacher provided the learners with pre-filled graphic organizers with collocations. In the individually-generated group, the teacher provided the learners with a list of words in groups, and they had some minutes to generate their graphic organizers. In the cooperatively-generated group, the participants had some minutes to generate their graphic organizers cooperatively with their peers. Using a pre-test, immediate post-test, and delayed post-test, the researchers examined the effects of these conditions on learners' collocation knowledge. The findings showed that all graphic organizer groups were more successful than the control group in developing learners' collocation knowledge. In addition, the mean value of the participants’ scores in the cooperative group was significantly more than that of the teacher-generated and individually-generated groups, and there was no significant difference between the mean scores of the teacher and individual-generated graphic organizer groups. تفاصيل المقالة