As the correlation of teacher professional development with student achievement has recently gained evidence in the scientific discourse on teacher professionalism and educational development, issues related to professional development have become a crucial component of nearly every education policy. In the context of reforms aiming at the improvement of educational systems, it has been widely acknowledged that teachers are to serve as essential agents of improving the educational system, rather than being one of the numerous 'variables' that need to be changed. This study explores the various formal and non-formal activities, as well as the institutional environment of in-service teacher learning, from the viewpoint of teachers serving in a metropolitan area of Malaysia.