Major concepts and findings related to the acquisition of early childhood bilingualism among Mexican American children are examined. Results are reported for empirical studies of bilingual acquisition, bilingual mother-child discourse, contextual and input parameters, interlanguage transfer, interactional language switching, and bilingual mother-child language acquisition. Among the other issues reviewed are tasks of native language acquisition, second language acquisition, incidence of bilingualism, linguistic input, sociocultural considerations, implications of language transfer for early childhood education, language switching discourse, cognitive development and language, bilingual education, and research considerations. (RW)