We supplement earlier published findings on the academic achievement of the immigrant second generation with an analysis of school contextual effects based on the same large data set used by the best-known prior analyses, the Children of Immigrants Longitudinal Study. A hierarchical model of contextual and individual-level effects on academic achievement and school attrition reveals patterns that reproduce those found in national student surveys but also others that are unique to the second generation. Among the latter are the resilient negative effect of length of U.S. residence on achievement across school contexts and the fact that strong effects of national origin on grades are attenuated in schools with high proportions of coethnics. Mexican-origin students display significant disadvantages in achievement and retention that are generally compounded, not alleviated, by the schools that they attend. A theoretical explanation of this pattern is advanced, and its practical implications are discussed.T he rapid growth of immigration during the past three decades has transformed the demographic structure of the United States and the nature of its interethnic relations. During the past intercensal period, immigration accounted for Ͼ70% of the growth of the American population; the foreign-born population reached 30 million, approaching the historic record of 15% of the total population attained in the 1920s. By 1997, a remarkable 62% of the population of Los Angeles was of immigrant stock (first or second generation) as were 54% of New York's, 43% of San Diego's, and 72% of Miami's population (1, 2).Although the initial attention of scholars and policy makers focused on the immigrants themselves, it has become clear over time that the long-term consequences of today's immigrant wave are more closely linked with the second generation and its chances for successful adaptation. Immigrant children and U.S.-born children of immigrants are the fastest growing segment of the nation's population under 18 years of age. By 2000, they approached 15 million or 1 in 5 of all young Americans (3, 4).Unlike first-generation immigrants whose concerns and aspirations are commonly centered in their country of origin and who frequently return there, the second generation is composed of U.S. citizens and most of its members are here to stay (5, 6). Most of this population is still young and the majority are still in school (4, 7). Hence, the principal outcomes of the adaptation process at this stage are educational: academic attainment and the likelihood of graduating vs. dropping out of high school. In this article, we examine the effects of the class and ethnic composition of the schools that second-generation youths attend in early adolescence on these key outcomes.Using data from the Children of Immigrants Longitudinal Study (CILS), the most extensive data source on the immigrant second generation to date, Portes and Rumbaut (8) analyzed the educational adaptation process of this population. Results were published in a series of a...