To further understand men's continued smoking during their partner's pregnancy and the postpartum period, a study was undertaken to explore women's perspectives of men's smoking. Using a gender lens, a thematic analysis of transcribed interviews with 27 women was completed. Women's constructions of men's smoking and linkages to masculine and feminine ideals are described. The findings highlight the ways women position themselves both as defenders and regulators of men's smoking. Femininities that aligned women with hegemonic masculine principles underpinned their roles in relation to men's smoking and presented challenges in influencing their partner's tobacco reduction. By positioning the decision to quit smoking as a man's solitary pursuit, women reduced potential relationship conflict and managed to maintain their identity as a supportive partner. Insights from this study provide direction for developing gender-specific tobacco reduction initiatives targeting expectant and new fathers. Indeed, a lack of intervention aimed at encouraging men's tobacco reduction has the potential to increase relationship tensions, and inadvertently maintain pressure on women to regulate fathers' smoking. This study illustrates how gender-based analyses can provide new directions for men's health promotion programmes and policies.