Instagram, as a popular social networking platform, allows users to share photos and videos with other users. This research investigated the effect of Instagram-assisted instruction on the learning of collocations and colligations by Iranian EFL learners. Fifteen participants who were selected based on a language proficiency test took part in this research. The participants were first pre-tested on their collocational and colligational knowledge. The collocational and colligational items that were answered incorrectly by 50 percent or higher were selected for treatment. Afterwards, the researchers prepared nine videos, containing 41 collocational and colligational items, and posted them on Instagram during a five- week instruction period. The participants were asked to watch the videos, and carry out the related exercises in the caption section of the post, through the usage of the comments sections on Instagram. After posting all the videos, the pre-test was run again as a post-test. The results indicated a significant difference between the mean scores of the pre- and post-test, highlighting the fact that the treatment had been effective. In addition, semi-structured interviews were conducted with 10 participants in order to find out their attitudes towards language learning via Instagram. The learners indicated a positive attitude towards using Instagram for their language learning purposes. In conclusion, the research showed that Instagram-assisted instruction, when properly implemented and designed, can be beneficial to the development of second language learning.