Using Sweden as a case study, a country where the number of women elected to the national parliament has steadily risen since the 1970s, Lena Wängnerud presents a novel approach on which characteristics inside a parliament help translate physical representation into substantive representation for women. Using three guiding principles: (i) the implementation of equal opportunities for women and men to influence internal parliamentary working procedures; (ii) the creation of room for women’s interests and concerns on the political agenda; and (iii) the production of gender-sensitive legislation, Wängnerud shows what are the necessary conditions for women’s needs, interests, and concerns to be adequately integrated into parliamentary processes. The Principles of Gender-Sensitive Parliaments book adds fuel to all these classical debates within the field of political representation and will bring attention to a wider audience on why electing women matters.