This study aims to investigate the effects Twitter has as a social networking platform on the development of Saudi EFL psychological variables (attitude, confidence, motivation, interest in L2 culture, social interaction and engagement), actual learning outcomes and the relationship between these psychological variables and their results. Twitter provides a valued accessible window to the target culture and promotes cross-cultural competence and comprehension that is focused on meaning rather than form, as well as repeated exposure to L2 cultural products, practices, perspectives and the target language. A sample of 39 students enrolled in an English course during the second semester of the 2014-2015 academic year, as well as two non-native English speakers (NNSs) working at the English Program, agreed to participate in the study. It adopts a combined inductive-deductive research approach to fulfil the research purpose and answer the research questions. The findings of this study underscore the latent use of the Twitter microblogging platform in EFL classes, as well as revealing the positive impact upon Saudi EFL students’ social interaction (engagement), enthusiasm and interest in learning more about L2 culture in English language classes.