Although qualities of mothering behavior have been consistently linked with children’s academic outcomes, mothers from different ethnic groups may emphasize different dimensions with their children. The present investigation aims to evaluate and compare the dimensionality of mothering in low-income African American (n = 151) and Mexican American (n = 182) mothers during early childhood and its predictive utility for children’s academic achievement. Video-recorded mother–child interactions with children at 2½ and 3½ years of age were rated using 6 mothering quality items from a widely used global rating system. A bifactor measurement model of these 6 items yielded a general sensitive support factor and a specific intrusive-insensitive factor. The bifactor model fit the data significantly better at both time points than either a single-factor or a 2-factor model. Invariance testing supported the stability of the measurement model across the 2 time points. Invariance testing by ethnicity indicated differences in factor loadings as well as mean levels of the specific factor of intrusive-insensitivity. The specific factor reflecting intrusive-insensitive mothering at age 2½ years was associated with poorer subsequent reading achievement for African American but not Mexican American children, suggesting the specific factor reflected qualitatively different parenting constructs for the 2 ethnic groups. Critical examination of what constitutes more optimal parenting yielded both similar and dissimilar characteristics and their relations across culturally different groups of families. Such knowledge should contribute to the development of more effective interventions for ethnically diverse families.