This synthesis research has aimed to identify the features of blended learning environments which support self-regulatory learning strategies in high school students. The statistical population was derived from five foreign databases, consisting of 128 articles from 2017 to 2020. The data obtained were integrated using Sandelowski & Barroso's meta-synthesis method (2005). STROBE Checklist was used to control the quality of the study, and 22 articles were identified and selected for the final analysis. As indicated by the results, first of all, the frameworks used in the studies describe blended learning environments from the point of view of motivational strategies and learning strategies, and based on such a description, a starting point is provided for future research in order to overcome designing problems regarding students' self-regulatory strategies in blended learning environments. Secondly, other studies and research will also benefit from this analytical approach for the description and support of self-regulatory learning in blended learning environments. The capability to describe blended learning environments in a systematic fashion opens doors for a series of practical interventions, this facilitating further studies in the self-regulatory field. This will help designers address learners' self-regulatory strategies with greater accuracy.