For open access to the publication, visit https://rdcu.be/cgITe. To download the full spreadsheet of reviewed articles, visit http://bit.ly/retrievalpracticereview. For more information about this project, visit http://retrievalpractice.org/review. For questions, please email Dr. Pooja K. Agarwal at ask@retrievalpractice.org. **Abstract**: Given the growing interest in retrieval practice among educators, it is valuable to know when retrieval practice does and does not improve student learning—particularly for educators who have limited classroom time and resources. In this literature review, we developed a narrow operational definition for “classroom research” compared to previous reviews of the literature. **We screened nearly 2,000 abstracts and systematically coded 50 experiments** to establish a clearer picture of benefits from retrieval practice in real world educational settings. Our review yielded 49 effect sizes and a total n = 5,374, **the majority of which (57%) revealed medium or large benefits from retrieval practice**. We found that retrieval practice improved learning for a variety of education levels, content areas, experimental designs, final test delays, retrieval and final test formats, and timing of retrieval practice and feedback; however, **only 6% of experiments were conducted in non-WEIRD countries**. Based on our review of the literature, **we make eight recommendations** for future research and provide educators with a better understanding of the robust benefits of retrieval practice across a range of school and classroom settings.