The ability to regulate one's emotions and behaviors is essential for adaptive functioning in society. We investigated whether parental mind-mindedness--parents' tendency to treat their children as mental agents--in infancy and toddlerhood predicts school-age children's self-regulation. The sample consisted of 125 mostly Dutch and White families. We assessed mothers' and fathers' appropriate and nonattuned mind-related comments during free play with their 12- and 30-month-old child (70 girls and 55 boys). We measured children's physiological, temperamental, and behavioral self-regulation when children were 4 1/2 years old. Fathers' appropriate mind-related comments predicted children's higher temperamental and behavioral self-regulation and mothers' and fathers' nonattuned mind-related comments predicted children's lower physiological and temperamental self-regulation. Our findings emphasize the importance of both parents' mind-mindedness in children's socioemotional development.