In this study, the author examined the professional knowledge that teachers use in order to assess and respond meaningfully to children’s interests. The findings revealed that personal and idiosyncratic nature of teachers’ knowledge gained in family, center and community contexts. The author argues that the personal, informal knowledge became infused with professional knowledge that influenced teacher curriculum decision-making and pedagogical practices. This informal knowledge can be described as an analytical framework of funds of knowledge. The teachers use the funds of knowledge in their interactions with children in complex and connected ways.