The current review employed bibliometric review methods to analyze 14,130 Scopus-indexed documents on problem-based learning published from 1972 through the end of 2019. The goals of the review were to describe the landscape and analyze the evolution of topical foci of interdisciplinary research on PBL over the past five decades. The review identified the accumulation of a substantial interdisciplinary corpus of research on PBL that is significantly larger than the literature on other approaches to active learning. The growth trajectory of the literature on PBL started out "low and flat" during the 1970s and 1980s but steadily gained momentum in subsequent decades, with 58% of the PBL literature published between 2010 and 2019. PBL has achieved an impressive scope of global research over the past 45 years, with a significant number of studies published from emerging regions of the world, especially during the past decade. While a long-term body of research has accumulated on the learning outcomes of PBL, the research front has begun to shift towards the study of self-directed learning, student satisfaction, self-efficacy, critical thinking, and cooperation. Research and practice challenges identified in the review focus on establishing the scope of use and efficacy of PBL across different cultural contexts and more systematically summarizing and synthesizing the use of PBL outside of the health professions.