Social media is part of the journalistic routines in all mass media. News company-managers develop actions and strategies to include the uses of social media in the professional field. Nevertheless, in spite of their professional penetration, the level of trust that journalists have in these platforms is low compared to traditional mass media. The main objective of this paper is to find out how Spanish journalists are using social media. The hypothesis is that social media doesn't hold enough trust amongst journalists, despite the fact that they use social media to look for information and to contact sources. An online survey, conducted among more than 400 Spanish journalists (newspaper, television, radio, internet and freelancers), showed that social media is used by most Spanish journalists but their trust in these new social channels is lower than in traditional mass media.