Being able to speak or communicate orally is an ultimate goal for most English language learners. Thus, teaching speaking is a main component of the curriculum in most communicative-based English language classrooms. However, teachers struggle to teach speaking in English language classrooms. Two main reasons contribute to this struggle: insufficient time for speaking practice in language classrooms and students' unwillingness to communicate due to anxiety. Asynchronous Computer-Mediated Communication (ACMC) may have the potential to provide a solution to this difficulty. A widely accessible mobile application that can provide an easily implemented ACMC tool is WhatsApp. The current case study explored the potential use of WhatsApp for teaching English speaking in an English as a Foreign Language (EFL) context. 15 Saudi EFL learners of English were recruited to participate in the present study. A mixed-method approach comprising pre and post-tests, closed-ended questionnaire, and semi-structured interviews were used to collect the data for the current study. The findings showed that using WhatsApp can have the potential for improving EFL learners' speaking performance, increasing their motivation and attitude towards speaking, and decreasing their anxiety and fear of making mistakes when speaking. WhatsApp can provide an effective platform for teaching speaking in an EFL setting where there is a scarcity of time available for oral communication.