The efforts were made in the present study to seek two objectives: determining the effect of Telegram as a social network on second language achievement of Iranian foreign language (EFL) learners, and exploring the EFL learner’ attitude toward using Telegram for language learning purposes. To this end, 40 EFL learners were randomly selected and then divided into two groups of experimental and control. The experimental group did their exercises through Telegram as a collective language learning activity at home, while members of the control group did the exercises in their individualistic specific ways. After the treatment, the results of Independent-Samples t-test showed that the experimental group outperformed the control group. The results of interview indicated that EFL learners mostly had never used any kind of social media in a collective manner for language learning. The findings of this study might have some implications for teachers to help them employ social media as an educational tool, for language learners to indicate the advantages of using social media for language learning, and for material developers to design activities in textbooks which need to be done through social media in a collective manner. پرونده مقاله