This study used a longitudinal design to examine whether effortful control mediated the associations of parental education and home environment quality with preacademic knowledge in toddlers and young preschoolers. The sample consisted of 226 children (2 to 4 years of age at T1) from socioeconomically disadvantaged backgrounds. Parents provided data on parent education and home environment quality. Children completed effortful control, early literacy, and early math assessments. T2 effortful control partially mediated the associations of T1 parental education and T1 home environment quality with T3 emergent literacy after accounting for child age, gender, race/ethnicity, T1 effortful control, and T2 early literacy. T2 effortful control partially mediated the association between T1 parental education and T3 emergent math after accounting for child age, gender, race/ethnicity, T1 effortful control, and T2 early math. Prior to entry into preschool, parental education and home environment quality may shape effortful control which in turn influences preacademic knowledge. (author abstract)