The purpose of the study is to diagnose the importance of social media for self-esteem, modes of online self-presentation and body image behavior of young adults. The monograph presents the research results which confirm that, among other things, for about 30-40% of young adults, social media are a space that significantly affects attitudes toward their own bodies. This is because they constitute a space for creating one’s own image, a source of motivation to engage in behaviors aimed at improving body image and taking care of one’s appearance, but also a space for social comparisons relating to one’s body image. The conclusion emphasizes the importance of forming a strong “bodily self” and an internal locus of control, the need for prevention of disorders related to body image disorders, psychoeducational interventions and the role of health education in the context of the research issue undertaken in the study.