The subject of this thesis is media literacy. The theoretical section describes the media and its types, the media features and the ways of media manipulation. The following chapter describes media literacy thoroughly. It indicates its application and the ways in which it can be improved at the institutional and personal level. Media competence, media pedagogy as well as media education are being interpreted. The paper describes the effects of the media and their influence on society and individuals. A key characteristic of media competence or protection against the harmful effects of the media on society is critical thinking, which is crucial because of the fact that the media user easily falls under the "programming" of media channels and is no longer able to think independently about current social events or media messages. Forementioned “programming” impacts thoughts of the user, his attitude, values, etc. The research was conducted with an online survey questionnaire on a sample of 453 preschool teachers. The conducted research found that preschool teachers have an interest in further professional development, but there are still a few who are not aware of this need. Furthermore, the opinions and media competencies of preschool teachers were examined, giving results that indicate an insufficient understanding of the concept of media literacy. The availability of materials and equipment indicate that there is still room for improvement in early and preschool education. Competent persons and institutions responsible for the quality and implementation of the process of early and preschool education should work on encouraging and ensuring adequate education for preschool teachers and promote the importance of media education to the principals of preschool institutions. Also, the reform of the education system is inevitable, which will more closely define the aim and processes of media literacy.