The aim of this paper was to theoretically explain the principle of media and media literacy of children of early and preschool age within their psychophysical development, to show the impact of the media on children and to specify parental roles in media literacy of children. The media are becoming more and more present in our lives and we need to know how to use them properly. Proper media use requires critical thinking, moral reasoning, and self-control. These and other essential cognitive and emotional abilities in early and preschool children have not yet reached the required level of development for independent interpretation of media messages to be protected from the negative influences of the media. There are certain values, false realities, stereotypes and prejudices in the media, and very easily and often children can encounter cybercrime and cheating, manipulation, violence and pornography through the media. Therefore, children with the media must not be left unattended and need to be media literate. An important precondition for children's media literacy is the media literacy of parents, and the cooperation of parents and educational institutions is important, as well as the cooperation of the entire community. Educators can help media literacy for parents through educational workshops, parent meetings, educational flyers, notice noards and so on. Media literacy is important because this way we get to know the media, the ways in which they are used and the impact they have on users. Impacts can be both positive and negative, and consequences short-term and long-term regardless of the time of onset and behavior. The more we know about this topic, the better we will be able to act to limit negative impacts and encourage the use of content with positive and long-term consequences. The influence of the media on children, if not controlled, is in most cases harmful, and mostly on cognitive, linguistic and socio-emotional development causing behavioral disorders, attention disorders and hyperactive disorders, memory problems, loss of self-control, poor vocabulary development and other developmental problems. Parents have the greatest influence on the direction of a child's development and they are intermediaries in the use of the media. Their role is to find quality media content appropriate to the child's age and to put a time limit on the use of media, but also to discuss the content together with the child and by that develop a critical attitude and abillity to differentiate reality from imagination. In addition, parents are obliged to organize quality days of early childhood in which the child has time for free play, but also time to read stories from a children's book.