We considered how different forms of child knowledge (i.e., mothers’ reports of taking their child's perspective, their accurate knowledge in the form of precise predictions of their child's ratings regarding distress/comforting and compliance/discipline situations, and their perceived knowledge) are differentially associated with mother‐reported autonomy support (i.e., providing meaningful rationales, providing choice, and acknowledging feelings; Koestner, Ryan, Bernieri, & Holt, ). Mothers and their children (141 dyads, M = 11 years old at Time 1) participated in a two‐wave longitudinal study with assessments made two years apart. The only form of knowledge that predicted changes in autonomy support was perspective‐taking. Autonomy support, in turn, indirectly predicted changes in distress/comforting accuracy through child‐reported self‐disclosure and directly predicted changes in perceived knowledge. These findings underline the importance of differentiating among forms of child knowledge in the study of socialization processes.