This study examined the relationship between early maternal knowledge of child development and later quality of parenting behaviors. Differences by race/ethnic group were also examined. Mother-infant dyads (N=378) participated in the study. Mothers completed the Knowledge of Infant Development Inventory (KIDI) when the infant was 2-4 months, and mother-toddler dyads were videotaped in their homes at 16-18 months. The Home Observation for Measurement of the Environment Inventory (HOME), Parent/Caregiver Involvement Scale (P/CIS), and Nursing Child Assessment by Satellite Training (NCAST) were used to measure quality of mother-toddler interaction. A series of hierarchical multiple regression analyses was conducted controlling for confounding demographic variables. Results revealed no significant main effect of maternal correct estimation of child development on quality of parenting, but there was a significant main effect of maternal underestimation of child development on quality of parenting during a teaching task. There was also a significant interaction of maternal knowledge and race in relation to quality of parenting behavior. Implications for generalizability and interventions are discussed.