The goal of this study was to examine whether attachment security and child temperament predicted differences in the elaboration and emotional content of mother-child discourse in 2 contexts and whether those differences were related to a child's socioemotional development. Fifty-one preschool children and their mothers were videotaped reading a storybook and discussing the child's previous behavior. These conversations were coded for maternal elaboration and emotional content. Mothers also completed reports of child temperament, attachment security, and social behavior. Children completed measures of emotional understanding, behavioral internalization, and representations of relationships. The findings suggested that both aspects of mother-child discourse were related to attachment, temperament, and socioemotional competence, although the findings varied depending on the context of the discourse.