Early differences in family SES, child language production, and IQ were related to outcomes in early elementary school in the present prospective, 10-year longitudinal study. In a prior study of family interactional variables associated with language learning, major differences in parenting (i.e., time, attention, and talking) were found to be associated with differences in child productive vocabulary between 7 to 36 months of age, and child IQ, favoring higher-SES parents. Lower-SES children were exposed less often than higher-SES children to diverse vocabulary through their parents' attention and talking, and they were prohibited from talking more often. In the current study, 32 children involved in the earlier study were repeatedly assessed between 5 to 10 years of age, while in kindergarten through third grade. Results indicated that SES-related differences in child language prior to school were predictive of subsequent verbal ability, receptive and spoken language, and academic achievement assessed on standardized tests in kindergarten through grade 3. However, none of the predictor variables were related to direct measures of elementary schooling. When combined with a composite SES indicator, early child language production significantly increased the variance accounted for in the prediction of elementary language and academic competencies in each subsequent year in elementary school. Implications are discussed in terms of the stability of performance on language and academic performance measures of children who entered school with different early language learning experiences, and the need to consider early home- and school-based intervention designed to prevent or ameliorate these trends.