Study goals were to assess: (1) the development of academic interests from middle childhood through late adolescence, (2) the degree to which junior high and high school transitions, parents' educational expectations, interests, and education, were related to changes in academic interests, and (3) the longitudinal links between youth's academic interests and school grades. Participants were mothers, fathers, and two siblings from 201, White, working and middle class families who were interviewed in their homes on up to 9 annual occasions. Multi-level model analyses revealed overall declines in youth's interests over time, with boys showing more rapid decline than girls. Mothers' educational expectations were positively related to youth's interests, and youth's interests declined less when fathers had more education. The transition to junior high, but not high school, was linked to decline in interests, but this was buffered by mothers' academic interests. Declines in youth's academic interests were linked to declines in school grades.