Rather than exploring once again what the concept of power can mean for constructivists, this article analyses what constructivism implies for doing a conceptual analysis; here, of power. It will try to show that besides an analytical assessment (`what does power mean'), a constructivist conceptual analysis includes a study of the performative aspects of concepts (`what does `power' do'?), which, in turn is embedded into a conceptual history or genealogy (how has `power' become to mean and able to do what it does?'). The analysis will show that a neutral or descriptive meaning of power cannot be found, since the meaning of power is always embedded in a theoretical context; hence conceptual and theoretical analysis interact with each other. It will further argue that attributing `power' has the effect of `politicising' issues, moving actions into the scrutiny of a public realm where justifications are needed. Finally, it sketches one hypothetical lineage for understanding the origins of these particular performative effects, which relates developments in German political theory to political realism in International Relations. At the same time, the article is meant to convey a more general point for the relationship between constructivist conceptual analysis and power: by stressing the reflexive relationship between knowledge and social reality, such a conceptual analysis is itself part (but only part!) of a more general constructivist power analysis.