Continuous professional development (CPD) is important for teachers in attaining sustainable education. Accordingly, exploring teachers' perceptions could be a significant endeavor as teachers' beliefs impact their classroom practices, thereby, impacting student learning and, thus have educational implications. Therefore, this study was designed to investigate this fundamental issue via establishing professional development workshops to train teachers in order to promote sustainable professional growth. It examined 86 EFL teachers' beliefs and attitudes toward CPD before and after attending workshops for professional development. The data were collected through a questionnaire and a follow-up interview. Paired-samples t-tests were run to measure differences between responses of pre and post surveys. Moreover, raw frequencies and percentages were calculated in order to prioritize the items the teachers selected in each variable. The findings demonstrate that beliefs about CPD can change. Survey data collected before and after professional development workshops revealed a statistical significant shift in EFL teachers' beliefs. This finding was also supported by semi-structured interviews. In addition, the results also revealed that the participants perceived customized professional development programs with professional development framework as a beneficial tool to be included in the professional development programs. The study may have some pedagogical implications to be utilized in the educational process directed at sustainable professional development.