The current interest in evaluating teachers and teacher education programs provides an opportunity to consider the education of diverse learners in K-12 schools in the United States. We address teaching English language learners (ELLs), a rapidly growing population. Challenges lie in holding content teachers of ELLs accountable as they are not adequately prepared to teach ELLs. In this article, we outline complexities surrounding the definition of the quality of teaching content to ELLs, provide an overview of existing teacher evaluation instruments, and discuss the difficulties in using ELL test scores to estimate the teacher contributions to academic growth of ELLs.