This study is a systematic review of 20 years of research on the usage of virtual reality (VR) in K-12 and higher education settings, which aims to consolidate, evaluate, and communicate evidence that can inform both the theory and practice of VR-based instruction. A total of 149 articles were selected from three major academic databases using search strings and manual screening protocols. The literature analysis emphasized four interrelated aspects of VR-based instruction: instructional context, instructional design, technological affordances, and research findings. The results revealed evolving trends in the VR literature in terms of publication patterns, pedagogical assumptions, equipment usage, and research methodologies, as well as the contextual factors behind VR adoption in education. Additionally, a meta-analysis was conducted to examine the efficacy of VR-based instruction, with results indicating an overall medium effect and several moderating factors. Finally, practical implications and a future research agenda for VR-based instruction are discussed.