This study is a response to the research and request presented by Bang and Midelfart (2010), to further investigate the effect dialogue can have on management team s effectiveness. The purpose of the study was to investigate and explain the effect of team psychological safety on task performance and team member satisfaction, with dialogue as a mediator in this relationship. 215 Norwegian and Danish management teams in the private and public sector were studied. As expected, team psychological safety and team effectiveness was positively associated, supporting hypothesis 1a and 1b. Furthermore, dialogue was positively related to team effectiveness, supporting hypothesis 2a and 2b. Finally, the results indicate that dialogue partially mediates the relationship between team psychological safety and team effectiveness when controlling for management team size and team level.