This research aims to find out the motivation, effectiveness, and challenges of PBI alumni in speaking English at community of practice. This study used qualitative research to collect the data through interviews. The participants of this study were six PBI alumni of UIN Ar-Raniry who are joining one of community of practice in Banda Aceh. The results show that PBI alumni were motivated to join the community of practice because they wanted to learn and practice English for some reasons, such as intrinsic or extrinsic motivation. Furthermore, this study also found out that learning English together in a community of practice is fun and flexible. After joining the community, they learned new vocabulary and improved their fluency in speaking English. Otherwise, they also faced challenges in joining the community of practice, such as a lack of confidence, a lack of vocabulary and a struggle to manage their time in participating every community’s meeting.