We examined reciprocal associations between parent-adolescent conflict and academic achievement over a 2-year period. Participants were mothers, fathers, and adolescents from predominantly White, working and middle class families (N = 168). After accounting for previous academic achievement, parent-adolescent conflict predicted relative declines in academic achievement 2 years later. After controlling for relationship quality at Time 1, lower math grades predicted relative increases in parent-adolescent conflict 2 years later among families with less education. (Contains 1 table and 3 figures.)