Infants would need to interact with systematic educational models, and experiences linked to receiving help from others, especially in the context of early education. With the aim of describing and interpreting preschool teachers' subjective theories about the development, teaching, and learning of prosocial behavior, we conducted an interpretative and descriptive study using a case study with qualitative methodology. We used a convenience sampling in which episodic interviews and discussion groups were carried out to 16 preschooler teachers from a north city of Chile. Data was analyzed by using techniques of topic coding and grounded theory. From this analysis, essentialist subjective theories of human nature, infancy and prosociality were found, which support (1) preschooler teacher' subjective theories about how prosociality develops, teaches and learns in young children, in addition to supporting (2) poor pedagogical practices of preschool teachers. Finally, results are discussed in the light of the current literature of prosocial behavior, proposing new areas of topic research and some suggestions to promote education in prosociality.