This paper used cross-lagged panel models to test the longitudinal interplay between maternal cultural socialization, peer ethnic-racial discrimination, and ethnic-racial pride across 5th to 11th grade among Mexican American youth (N = 674, M_age  = 10.86; 72% born in the United States; 50% girls; Wave 1 collected 2006-2008). Maternal cultural socialization predicted increases in subsequent youth ethnic-racial pride, and youth ethnic-racial pride prompted greater maternal cultural socialization. However, peer ethnic-racial discrimination was associated with subsequent decreases in ethnic-racial pride. The magnitude of these associations was consistent across 5th to 11th grades suggesting that maternal cultural socialization messages are necessary to maintain ethnic-racial pride across adolescence, thus families must continually support the development of ethnic-racial pride in their youth to counter the effects of discrimination.