Problem-based learning (PBL) represents a major development in educational practice that continues to impact both courses and disciplines worldwide (Schmidt, van der Molen, te Winkel, & Wijnen, 2009a). The chapter first outlines what PBL is and when, why, and how it developed. Next, it discusses what PBL aims to establish. The key elements of PBL are reviewed, followed by empirical research on the effects of PBL. Finally, it concludes the chapter with critical remarks and final notes.