Women's narratives of their breastfeeding experiences are sites of construction and reconstruction of self as they undertake moral work in relation to feeding their baby. We engaged Foucault's ‘technologies of the self’ and his notion of ethics (the relationship with self) to examine that moral work (individual actions rather than adherence to universal moral codes) in relation to women's subjectivity constructed in interviews with 49 women from the UK. Four categories of moral work were identified: biographical preservation, biographical repair, altruism and political action. We describe each of these and conclude that women's embodied experience and sense of self are disciplined within current, limited, often punishing discourses by undertaking painful moral work in order to maintain or repair their subjective positions. We suggest the development of new subject positions around infant feeding practices.