In this qualitative case study, we explored how ten EFL teachers who attended an in-service staff development programme subsequently integrated professional learning into their classroom practice, and which staff development practices were effective in this process. We triangulated data from interviews, observations, and document analysis. The data were subjected to content analysis. The results indicated that the transformation of learning experiences started with self-reflection, which initiated changes in teachers' pedagogical beliefs. The results further indicated that although major changes in teachers' practice followed the changes in their pedagogical beliefs, there was an interactive relationship between the teachers' beliefs and practice in the long term. The results revealed that this relationship could be regarded as part of a more complex dynamic system where teacher self-efficacy and motivation operated as an affective filter between teachers' beliefs and practice.