We tested the hypothesis that mother–child warmth and responsiveness would moderate the link between young children's theory of mind skills and self-worth. Participants included 125 same-sex pairs of 3.5 year-old twins and their mothers. A battery of tests was individually administered to measure the children's theory of mind skills and verbal intelligence, and their self-reported self-worth was assessed using a puppet interview. Following visits to the families' homes, the observers completed ratings of warm responsive mother–child behavior based on videotaped unstructured and structured observations. As expected, warm responsive behavior moderated the relation between their theory of mind and the child's self-worth. Their theory of mind was positively associated with self-worth in warm responsive mother–child dyads, and there was weaker evidence that their theory of mind may be negatively associated with self-worth in less warm, unresponsive mother–child dyads.