Children use electronic screens at ever younger ages, but there is still little empirical research on how and why parents mediate this media use. In line with Vygotsky’s zone of proximal development, we explored whether children’s media skills and media activities, next to parents’ attitudes about media for children, and several child and parent-family characteristics, predicted parental mediation practices. Furthermore, we investigated children’s use and ownership of electronic screens in the bedroom in relationship to the child’s media skills. Data from an online survey among 896 Dutch parents with young children (0–7 years) showed that children’s use and ownership of TV, game consoles, computers and touchscreens, primarily depended on their media skills and age, not on parent’s attitudes about media for children. Only touchscreens were used more often by children, when parents perceived media as helpful in providing moments of rest for the child. In line with former studies, parents consistently applied co-use, supervision, active mediation, restrictive mediation, and monitoring, depending on positive and negative attitudes about media. The child’s media skills and media activities, however, had stronger relationships with parental mediation styles, whereas age was not related. Canonical discriminant analysis, finally, captured how the five mediation strategies varied among infants, toddlers, pre-schoolers, and early childhood children, predominantly as a result of children’s media skills, and media activities, i.e., playing educational games and passive entertainment use.