Breastfeeding is a practice which is promoted and scrutinized in the UK and internationally. In this paper, we use interpretative phenomenological analysis to explore the experiences of eight British first-time mothers who struggled with breastfeeding in the early post-partum period. Participants kept audio-diary accounts of their infant feeding experiences across a 7-day period immediately following the birth of their infant and took part in related semi-structured interviews a few days after completion of the diary. The overarching theme identified was of a tension between the participants' lived, embodied experience of struggling to breastfeed and the cultural construction of breastfeeding as 'natural' and trouble-free. Participants reported particular difficulties interpreting the pain they experienced during feeds and their emerging maternal identities were threatened, often fluctuating considerably from feed to feed. We discuss some of the implications for breastfeeding promotion and argue for greater awareness and understanding of breastfeeding difficulties so that breastfeeding women are less likely to interpret these as a personal shortcoming in a manner which disempowers them. We also advocate the need to address proximal and distal influences around the breastfeeding dyad and, in particular, to consider the broader cultural context in the UK where breastfeeding is routinely promoted yet often constructed as a shameful act if performed in the public arena.