This study examined the influence of using Instagram on EFL learners' critical thinking in language institutes. The participants were 98 students (40 males and 58 females) studying English at three branches of a language institute in Iran who were 20-24 years old and shared the same L1 which was Persian. They were selected through purposive sampling. Their proficiency in English was checked by administering DIALANG. Based on their scores on DIALANG, two equal groups were formed as experimental and control. As the pretest, California Critical Thinking Skills Test and California Critical Thinking Disposition Inventory were utilised. Afterward, the experimental group were taught in class and via Instagram, while the control group were taught only in class without using Instagram. The treatment lasted for 12 weeks each week for two sessions each session for 2 h. Then the posttest, which included administering California Critical Thinking Skills Test and California Critical Thinking Disposition Inventory was administered. The two groups got nearly the same scores on the pretest which showed their same proficiency level, but, their performances on the posttest were significantly different and the experimental group performed much better than the control group. This study may have implications for teacher trainers, supervisors, teachers, and textbook writers.