Background: Self-determination theory, which deals with motivation and personality, comprises three factors of autonomy, competence and relatedness that can be influenced by the features and potentials of social networks. Objectives We aimed to investigate the influence of social networks on the three main factors of the self-determination theory in learners. Methods: The present case-control study with a pretest-posttest design was conducted among 40 Iranian Ph.D. students who lived in Schengen area countries. Students were randomly divided into control (n = 20) and experimental (n = 20) groups. Before and after holding training sessions through a social media (Facebook) and face to face (FTF) education, Test of English as a Foreign Language (TOEFL) and the intrinsic motivation inventory were used for data collection. The intrinsic motivation inventory is a valid instrument that evaluates the three factors of autonomy, competence and relatedness. Results: the results indicated a significant difference between the two groups in terms of the three factors. The means of all the three variables improved significantly in the social network group as compared to the FTF group (P = 0.00). Although competence had improved in both groups, this improvement was greater in the social media group relative to the FTF group (P = 0.00). Conclusions: Social networks provide better learning experiences. They improve learning outcomes as they boost learners’ relatedness, competence and autonomy.