Professional development (PD) is critical for maintaining and developing teachers' qualities and competencies; however, how to make PD more effective in relation to EFL teachers' expectations and examine their satisfaction levels with PD activities organized in a foreign language center remains a major concern for administrators, researchers, and teachers. The purpose of this study is to explore EFL instructors' expectations and levels of satisfaction with the PD activities that they have participated in. This study used both quantitative and qualitative research methods, including questionnaires and interviews to answer the research topics indicated above. The study involved 50 teachers at an English Language Center, in Can Tho City, Vietnam. According to the findings, EFL teachers have high expectations for (1) PD content, which focuses on improving lesson planning and student outcomes, as well as learning how to create a supportive learning environment; (2) coherence of PD with teachers' needs and students' needs and interests; (3) opportunities for active learning, such as observing more experienced teachers or being mentored by experts; and (4) duration of PD, which should be ongoing throughout the year and a year-long program. EFL teachers were also satisfied with (1) the PD content, (2) the coherence, and (3) the duration of the PD, according to the findings. Some recommendations for increasing PD characteristics are offered based on the primary findings. [For the full proceedings, see ED654100.]