Mixed-methods explored the potential for using Sure Start Children’s Centres (SSCCs) to deliver an intervention to improve the diets of disadvantaged women and their children. In an ‘expert’ discussion, SSCC staff described gaining women’s trust, meeting needs and bringing about change as key to engaging women successfully. Structured observations in SSCCs showed they host activities in an environment conducive to building relationships and meeting women’s needs. However, staff often missed opportunities to support women to make dietary changes. These data suggest that an intervention to help staff make the most of these opportunities would have the best chance of success.