Problem-based learning (PBL) is a pedagogical approach that shifts the role of the teacher to the student (student-centred) and is based on self-directed learning. Although PBL has been adopted in undergraduate and postgraduate medical education, the effectiveness of the method is still under discussion. We employed a scoping review to appraise available international evidence concerning to the effectiveness and usefulness of PBL methodology in undergraduate medical teaching programs. We applied the Arksey and O’Malley framework to undertake a scoping review. A search of literature published in English and Spanish identified one hundred and twenty four publications eligible for this review. Despite the fact that this review includes many studies, their design is heterogeneous and only a few provide a high scientific evidence methodology (randomized design and/or systematic review with meta-analysis). Furthermore, most are single-center experiences with small sample size and there are no large multi-center studies. PBL methodology obtains a high level of satisfaction, especially among students. It is more effective than other more traditional (or lecture-based methods) at improving social and communication skills, problem-solving and self-learning skills. Knowledge retention and academic performance are no worse (and in many studies are better) than with traditional methods. PBL is not universally widespread, probably because it requires greater human resources and continuous training for its implementation. More comparative and randomized studies and/or other systematic reviews and meta-analysis are required to determine which educational strategies are the most suitable for training the doctors of the future.