Background. Executive functions are actively developing in children of preschool age. Executive functions’ development is also influenced by the way children are using digital devices. Joint media engagement is one of the parameters of digital device usage that has been poorly studied so far, although this is of great importance from the point of view of cultural-historical psychology. Objective. Our research aimed to explore the association between young children’s development of executive functions over a year, and their joint media engagement with parents and siblings in preschool children. Design. Four hundred ninety (490) typically developing children (52% of them were boys) participated in the study. It was a longitudinal study: during the first stage, the children were 5-6 years old; the second stage followed one year later. The NEPSY-II subtests (Inhibition, Statue, Memory for Designs, Sentences Repetition) and the Dimensional Change Card Sort were used to assess executive functions. A questionnaire for mothers was used to get information about the children’s joint media engagement and screen time. Results. Children who watched video content and played video games together with their siblings developed more inhibitory control over the year than those children who did it alone. Co-viewing of video content with parents was associated with a decrease in cognitive flexibility over the year, as opposed to watching it alone. Conclusion. The obtained data allows us to conclude that joint media engagement is important for executive functions development, and that there are optimal formats of joint media engagement. Based on the limitations of this study, recommendations for future research were suggested.