Young children differ in their responses to failure, displaying mastery or helpless behavior patterns. We examine the moderating role of child temperament on the association between parent warmth/negativity and children's helpless responses to failure. Regarding temperament, we focus on tendencies to experience interest and sadness because they entail task engagement and withdrawal, respectively. We measured mother (n=150) expressions of positive and negative emotion during a teaching task, assessed temperament using LabTAB‐Preschool episodes, and coded helplessness during an impossible puzzle task. Maternal negative emotion during teaching was positively associated with helplessness, but only for children low in interest. Maternal warmth was negatively associated with helplessness, but only for children high in sadness; sadness did not moderate the relation between maternal negativity and helplessness. Findings provide support for parenting by temperament goodness‐of‐fit models and for a discrete emotions approach to temperament.