BACKGROUND: To accomplish the aims of public health practice and policy today, new forms of communication and education are being applied. Social media are increasingly relevant for public health and used by various actors. Apart from benefits, there can also be risks in using social media, but policies regulating engagement in social media is not well researched. This study examined European public health-related organizations' social media policies and describes the main components of existing policies. METHODS: This research used a mixed methods approach. A content analysis of social media policies from European institutions, non-government organizations (NGOs) and social media platforms was conducted. Next, individuals responsible for social media in their organization or projects completed a survey about their social media policy. RESULTS: Seventy-five per cent of institutions, NGOs and platforms had a social media policy available. The primary aspects covered within existing policies included data and privacy protection, intellectual property and copyright protection and regulations for the engagement in social media. Policies were intended to regulate staff use, to secure the liability of the institution and social responsibility. Respondents also stressed the importance of self-responsibility when using social media. CONCLUSIONS: This study of social media policies for public health in Europe provides a first snapshot of the existence and characteristics of social media policies among European health organizations. Policies tended to focus on legal aspects, rather than the health of the social media user. The effect of such policies on social media adoption and usage behaviour remains to be examined.