We examined the relations between the referent of parents and preschoolers’ mental state talk during a collaborative puzzle‐solving task (N = 146 dyads; n = 81 3‐year‐olds, n = 65 4‐year‐olds). The results showed that parents’ references to their own knowledge and beliefs (self‐referent cognitive talk), and references to their child’s knowledge and beliefs (child‐referent cognitive talk) were both related to children’s (primarily self‐referent) cognitive talk. We then tested whether any of the observed relations could be explained by the presence of conflicting perspectives within the collaborative interaction. Mediational analyses revealed that conflicting perspectives mediated the positive relation between parents’ production of self‐referent cognitive talk and child cognitive talk. By contrast, the positive relation between parents’ production of child‐referent cognitive talk and child cognitive talk did not depend on the presence of this type of conflict. These findings highlight an important mechanism through which parents’ references to their own mind might promote children’s developing mental state talk in collaborative contexts.