Background: Cumulatively, research indicates that teachers who are emotionally supportive and create positive classroom climates influence the outcomes of at-risk students in nontrivial ways. Prior research has also established that teacher behaviors that support autonomy, provide higher level thinking opportunities, and value students' social and cultural knowledge also contribute to achievement outcomes. Although research points to several specific aspects of teaching that affect the academic outcomes of students facing barriers, existing theory and research suggest that classroom dynamics do not unfold uniformly across various settings. To date, the chief means of addressing the problem of Hispanic English language learners' (ELLs') achievement has been a focus on language acquisition model effectiveness alone. Despite extant bodies of literature examining separately the contribution of classroom dynamics on student achievement and the effectiveness of language acquisition methods for ELLs, there has been no examination of the ways in which classroom dynamics may moderate language acquisition methods for ELLs. Research Questions: The present study examined the following research questions: (1) What teacher behaviors and student-level characteristics predict student achievement? (2) Do teacher behaviors moderate the relationship between language acquisition models and ELLs' achievement? Research Design: Sources of data in this study consist of student demographic variables and reading achievement for 995 students and classroom observation data using the Classroom Assessment Scoring System collected across 46 classrooms in an urban school district in Wisconsin. Hierarchical linear modeling was used to address the research questions. Results: A two-level hierarchical linear modeling analysis revealed that prior achievement, Hispanic and African American ethnicity, and eligibility for free lunch contributed significantly to the model, but gender did not. Teachers contributed markedly to student reading outcomes when they (1) incorporated student perspectives into instruction; (2) promoted autonomy and responsibility; (3) provided instructional opportunities to support higher level thinking; and (4) applied instruction to real-life applications. Cross-level interactions indicate that emotional warmth was particularly salient for ELLs in dual language immersion, whereas instructional support moderated the relationship between developmental bilingual education and reading achievement. Implications for teachers of students who are at risk for school failure are discussed. Conclusions/Recommendations: Findings from the present study suggest that developing teachers' emotional warmth and instructional support is particularly salient for teachers of ELLs, who must possess qualities associated with good teaching, both in general (such as content knowledge and pedagogical skills) and, more specifically, for ELLs (proficiency in bilingual education methods).