The main aim of this thesis is to explore how members of a certain Facebook-group, i.e. Save the Food – Malmö, share knowledge with each other. The main research questions in this thesis address whether the selected social media channel, i.e. Facebook, help to enhance this member-to-member knowledge sharing process, and what kind of knowledge is being shared. The thesis is based on theories that provide an overview of how knowledge is considered to be shared in the best ways across social media and what limitations these may have. Therefore, the theoretic framework is primarily based on knowledge management research and knowledge management in connection to social media. The general attitude among the respondents shows that social media are an useful tool for networking, information and knowledge sharing and that social media are a helpful tool for informal communication between groups members. Even though there are some negative attitudes towards Facebook among the respondents, this study shows, however, that the respondents still believe that there is considerable potential in using social media in relation to networking, knowledge sharing and organizing activities such as dumpster diving. The thesis is based on qualitative methods. The empirical data were collected through informant interviews. The results of the thesis show that social media, in this case Facebook, are used as a means to share knowledge within the ”Save the food – Malmö” group. However, due to the limitations pertaining to what kind of knowledge can be shared across social media channels such as Facebook and others, the knowledge sharing process needs to be complemented with interpersonal interaction between the members in real life to ensure the application and externalisation of the shared knowledge.