Parent’s beliefs about intelligence can influence children’s learning through parenting practices. It is unclear how parents’ perceptions of the child’s ability may affect these processes. This experimental study explored the joint effects of mothers’ growth mindset and perceptions of child competence on their learning involvement. Children (N = 121, 52% female, ages 9–15) completed a set of problem-solving tasks, and mothers were told that their children had either performed well or poorly; or received no feedback. In a subsequent problem-solving task, mothers’ growth mindset positively predicted supportive behaviors, and mothers’ low competence beliefs positively predicted unsupportive and controlling behaviors. No interactions were found. Findings suggest parental growth mindset may help foster positive parenting practices, regardless of their children’s academic competence.