Over the past decade, internet and politics scholarship has been concerned with the effects of the internet on forms of civic and political participation. Recent research has moved on to examine the effects of social networking sites like Facebook. Although past studies have generally found positive – albeit weak or moderate – relationships between social networking sites use and civic and political participation, reliance on cross-sectional surveys has not produced conclusive evidence of the direction of causality. We use a two-wave panel survey of 15 and 16 year olds to examine how Facebook use affects various forms of political and non-political entertainment-oriented participation (both online and offline). We find that Facebook use is positively related to civic and entertainment-oriented, but not to online or offline political, participation. Further analysis using structural equation modeling shows that prior levels of civic participation have a stronger effect on Facebook use than Facebook use has on civic participation. Facebook use only leads clearly to entertainment-oriented participation. The implications of these findings are discussed.