Background: Previous studies on augmented reality-enriched learning and training indicated conflicting results regarding the cognitive load involved: some authors report that AR can reduce cognitive load, others have shown that AR is perceived as cognitively demanding and can lead to poorer performance. Objectives: The aim of this study is to systematically analyse previous research on AR and cognitive load, including performance, and thus to be able to contribute to answering the question of the impact of AR on cognitive load when used in learning environments. Methods: This study applied the systematic review method. A total of 58 studies were identified and analysed using rigorously defined inclusion and exclusion criteria. The results are now reported as a synthesis. Results and Conclusions: Compared to other technologies, AR seems to be less cognitively demanding and also leads to higher performance. However, these results are based on media comparison studies that have been criticized for years. The spatial AR type is better compared to see-through AR. However, the latter can be improved by visual cues and the addition of learning activities, such as value-added studies have revealed. Major takeaways: The essential findings of this study are that the technology used, for example, AR glasses, can unnecessarily increase cognitive load and that still many studies focus on the comparison of AR with more traditional media. Less studies applied alternative research designs, for example, value-added comparisons. However, such designs are better suited to investigate design principles for AR-enriched learning environments, which can then in turn reduce cognitive load as well as positively affect performance.