This article examines constructions of gender in UN documents and peace operations. The focus is on gender mainstreaming: the kinds of notion of men and women that are produced in gender mainstreaming and what kind of effect mainstreaming has. Based on an analysis of the key UN documents and the fieldwork among Finnish peacekeepers in Kosovo, the argument is that gender mainstreaming documents and practices tend to rely on essentialized notions of women as victims and inherently peaceful. The consequences of this are twofold. On the one hand the international community is not able to see local women as agents of their own future. On the other, the participation of women in peacekeeping forces is promoted on the basis of an alleged pacifying effect on their male colleagues. As a result traditional gender roles are reinforced and the variations in masculinities and femininities are ignored.