Problem-based learning (PBL) is a unique form of pedagogy dedicated to developing students' self-learning and clinical practice skills. After several decades of development, although applications vary, PBL has been recognized all over the world and implemented by many medical schools. This review summarizes and updates the application and study of PBL in medical education through the literature published between 1993 and early 2017. It focuses on understanding real medical PBL courses and ways to improve PBL to achieve better learning outcomes. PBL aims to develop lifelong skills to solve practical problems rather than limiting learning to theoretical knowledge. To achieve this goal, strict and reasonable procedures need to be designed and implemented. Rigorous monitoring and timely feedback and evaluation are indispensable to constant improvements and perfecting of the process.