This entry introduces the complex and theoretically diverse concept of nonsuicidal self‐injury (NSSI). NSSI is defined as a form of self‐harm that does not aim for fatal outcome and must therefore be delimited from suicidal behavior with fatal intentions. Nevertheless, NSSI is considered a strong predictor for actual suicidal behavior. As a public health concern which affects adolescents in particular, NSSI is subject to efforts that aim at prevention and provision of help resources. Importantly, the media plays an integral role in the context of self‐harming behavior as it can have both detrimental and beneficial effects: on a continuum of effects, the media can (i) serve as a negative reinforcer promoting harmful behavior or (ii) act as a positive contributor by supporting favorable coping strategies and prevention. Among other determinants, such as intraindividual predisposition or susceptibility, the respective outcome largely depends on how NSSI is portrayed in the media. Thus, attention should be drawn to the role of the media in regard to NSSI – in terms of both research efforts and practical handling of NSSI content. In this, the focus is now largely on social media in particular, and algorithms and machine learning seem to be promising approaches.