This study aims to understand the Kenyan cross-party parliamentary women’s caucus success at representing women substantively despite ethnic division. The Kenyan case highlights a paradox: the cross-party parliamentary women’s caucus is successful in a country where politics is shaped by ethnic division, which contradicts existing theories suggesting that the many layers of identity politics would make it difficult for the members to cooperate on a common women’s agenda. The material was collected during ten weeks in Nairobi through interviews with women MPs within the caucus and through observation of meetings, events, and the daily work of the caucus. The findings suggest that women’s issues are perceived as non-political, and non-controversial, which makes it possible for the members to cooperate on a common women’s agenda. Kenya seems to be in an initial stage of gender mainstreaming where the caucus’s members cooperate on women’s fundamental rights, on which they can all agree. It is reasonable to believe that the political parties will develop ideological differences concerning women’s issues as Kenya achieves a certain level of gender equality. The cross-party parliamentary women’s caucus will, according to the findings, be essential to improve the substantive representation of women in the Parliament.