Alignment between standards and assessments is a fundamental component of the larger effort to ensure appropriate and fair use of standards-based assessments and achievement of successful standards-based reform. This article focuses on conceptual and technical issues as well as potential strategies in evaluating alignment between large-scale, standardized English language proficiency assessments and English language proficiency standards in the U.S. K-12 education context, as these assessments are used in high-stakes decisions about English language learners. Areas for future research are also discussed.