In this article empirical research regarding the best predictors of literacy achievement for English language learning students (ELLs) in English-only classrooms is reviewed. These students comprise an ever-increasing population in these settings, but there is considerable confusion in differentiating between ELLs who are low-achievement readers because of limited language proficiency and those who may have learning difficulties. Much research has highlighted the importance of phonological processes, particularly phonological awareness, on reading achievement for native English-speaking children and it seems that researchers have relatively recently begun to examine whether or not the same might hold for ELL children. The findings regarding this under-researched population are discussed and implications and recommendations for future research and practice are proposed.