This study examined 1) mothers' neural responses to pictures of boys and girls who confirmed or violated social expectations regarding toy preferences, and 2) whether neural sensitivity to targets that violated gendered expectations interacted with mothers' gender stereotypes. In an event-related fMRI experiment, 23 mothers of a 2-6 year-old child viewed and evaluated pictures of boys or girls with their favorite toy. Next, mothers gender stereotypes about children's toys and behavior, and internal motivation to behave without prejudice were assessed. Several neural processes were underlying parents' responses to children's behavior that violates gender-role expectations. Brain regions involved in mentalizing or storage of social knowledge, understanding goal-directed behavior, behavioral control, and conflict monitoring were activated when viewing child targets that violated gender expectations. In these brain areas, increased neural responses to targets that violated traditional gender expectations were associated with more stereotyped expectations about boys' and girls' toys and behavior.