© The Author(s) 2019. The purpose of this study was to examine whether parental self-efficacy (PSE) is associated with change in infant weight-for-length z score (WLZ) from age 3 to 12 months. Data were drawn from the Infant Care, Feeding, and Risk of Obesity study, conducted with low-income, African American mother–infant dyads (n = 127). PSE was measured at infant age of 3 months. Infant anthropometrics were measured at infant age of 3 and 12 months, WLZ change between these time points was calculated, and infants stratified into WLZ change categories (expected, excessive, or slow). To analyze the data, ANCOVA, multiple regression, and post hoc techniques were used. Controlling for infant birthweight, PSE at 3 months was associated with infant WLZ change (η2 = 0.05, p =.04). Mothers of infants who exhibited excessive growth had higher PSE than mothers of infants who exhibited slow growth (Tukey-adjusted p =.03). This finding suggests that infants of mothers with high PSE may have increased obesity risk, but more research is needed.