Project Lead the Way (PLTW) is a non-profit organization offering project-based STEM education curricula for K-12 students. As of 2015, PLTW was by far the largest pre-engineering program implemented throughout the United States with a presence in over 6500 schools. Since its conception in 1997, PLTW rapidly expanded and today covers all 50 states and the District of Columbia. The PLTW Engineering curriculum offers a sequence of courses that students may take over the course of high school, and many university programs allow students who complete this sequence the opportunity to earn college credit. The PLTW Gateway curriculum targets students in Grades 6-8 and the PLTW Launch curriculum targets K-5 students. See the PLTW website for current program titles. They now simply use PLTW Engineering, PLTW Gateway, and PLTW Launch.This study investigates the efficacy of PLTW efforts through a systematic literature review process. Specifically, we explored the following research questions:• After an initial data collection and literature reduction processes, we synthesized 31 articles that collected and analyzed empirical data related to PLTW. Our gathered literature included 16 journal articles, 11 dissertations, and 4 theses. Using an emergent coding process, we found that primary strengths of PLTW curricula include facilitating student interest in STEM (namely, engineering), motivating students to pursue STEM degrees, and providing teachers with effective professional development opportunities and support. However, weaknesses of PLTW include minimal evidence supporting PLTW participation as improving students' mathematics and science abilities, scheduling and space issues, and moderate financial costs for schools to participate in PLTW. Altogether, the literature collected varied widely and, as a result, each of these strengths and weaknesses requires further investigation. This study concludes with an identification of gaps in PLTW literature that scholars might utilize to focus future PLTWrelated investigations, which will in turn improve future PLTW and PLTW-related interventions.