In this article, we have used panel data from the Children of Immigrants Longitudinal Survey (N = 3,337) to test several mechanisms (English proficiency, friends with native parents, parental socioeconomic status [SES], educational attitudes, bilingualism, and family stability) by which mixed parents (one native, one foreign-born) affect their children's educational attainment differently from immigrant parents (both foreign-born), using a multiple mediator model. We found that children from mixed parents benefited from higher parental human capital and a higher English proficiency and were set back by lower educational attitudes and less stable family situation. However, bilingualism offered no significant advantages or disadvantages for children of mixed parents. Having more friends from native-born parents had a surprising negative effect. The total indirect effect was slightly negative and a substantial negative direct effect of growing up with mixed parents on educational attainment remains. Some of the effects depend on the sex of the native partner. Implications and limitations are discussed.