Traditional EFL speaking classes have several deficiencies, including a lack of authentic cultural context, limited practice opportunities due to class size and time constraints, and an absence of communicative context. These deficiencies hinder the speaking proficiency of EFL learners. In addition, although mobile-assisted language learning has been recognized as effective, there is a limited focus in existing research on its application to enhance EFL speaking skills within a social language learning environment. This research aimed to address these issues by designing a speaking learning activity for EFL learners using a mobile-assisted social language learning environment. The purpose was to provide enough opportunities and time for learners to practice their speaking skills in communicative, authentic and cultural contexts. The study investigated whether this designed learning activity benefited the learners' EFL speaking performance, including their pronunciation, fluency, vocabulary, grammar, and content. Our research question was as follows: Do language learners who attend the mobile-assisted social language learning activity perform better compared to language learners who attend the traditional language learning activity? Fifty-eight graduate students took part in the study and were randomly assigned to either a control group (who completed learning tasks using the traditional method) or an experimental group (who used a mobile social language learning app). The results indicated that the learners in the experimental group performed significantly better on the EFL speaking post-test than those in the control group. Therefore, it is recommended that the EFL speaking learning activity be conducted within a mobile-assisted social language learning environment as it can enhance learners' speaking abilities.