CThe article is a study of Latino immigrant parents' agency toward primary language (L1) instruction in the face of restrictionist language policy. Certain attitudes and characteristics were associated with advocacy for Spanish L1 instruction. Interviews conducted in an urban California school district among parents with different background characteristics and attitudes about L1 instruction following passage of an antibilingual education law showed conflicting influences on their consciousness by restrictionist state language policies and local community support for bilingual education. Parents' educational levels, experiences with bilingual education, and ties to the home country were also associated with the strength of their agency toward L1 instruction. Support for English-only instruction appeared to derive from hegemonic language policies and negative experiences with bilingual programs. Findings suggest that parent education about the advantages of L1 instruction and positive experiences with bilingual education are necessary to support informed parent agency in a language-restrictionist context. A concurrent nested mixed-methods design integrates quantitative and qualitative data within a macrocultural psychology framework. The study compares the language-restrictionist context of California with the situation of linguistic minorities in Europe and developing countries, and suggests the implications of findings for international research. (Contains 4 tables.)