Relations between mothers' tendency to comment appropriately on their 8-month-olds' internal states (mind-mindedness) and children's behavioral difficulties (Strengths and Difficulties Questionnaire) at ages 44 and 61 months were investigated in a socially diverse sample (N = 171, 88 boys). Controlling for maternal depressive symptoms, perceived social support, sensitivity, child language ability, and child gender, maternal mind-mindedness was negatively related to children's externalizing and internalizing behaviors specifically in low socioeconomic status (SES) families. Furthermore, behavioral difficulties at age 44 months mediated the relation between maternal mind-mindedness and behavioral difficulties at age 61 months, but only for low SES families. These findings are discussed with reference to possible ways in which mind-mindedness could inform interventions targeted at at-risk groups.