This study aims to investigate the use of mobile learning to provide pronunciation training for lecturers of english as a foreign language (efl) from vietnamese provincial universities. Mobile learning offers a potential solution for the delivery of professional development to lecturers based outside major cities thanks to its capacity to enable learning anytime, anywhere. Mobile learning and speech technology are expected to facilitate lecturers’ self-direct learning to fulfil their professional development needs using their own devices. This paper reports results from a pilot study which serves as the first phase of an ongoing design-based research project. The pilot study was carried out to explore the feasibility of an online pronunciation course and identify potential problems for future course iterations in the context of participants living outside major cities in a developing country. The objectives of the project are to establish and test a set of fundamental principles for mobile learning to be an effective way of providing online professional development for lecturers based outside major cities and to shed light on the necessary adjustments in course design to make it a scalable model for future education planning. In this study, both qualitative and quantitative data were collected during two iterations of an online pronunciation professional development course for efl lecturers from vietnamese provincial universities. Ascilite 2017 – conference proceedings – 34th international conference of innovation, practice and research in the use of educational technologies in tertiary education.All right reserved.