This review synthesizes research on English reading outcomes of all types of programs for Spanish-dominant ELLs in elementary schools. It is divided into two major sections. One focuses on studies of language of instruction, and one on reading approaches for ELLs other than bilingual education. A total of 14 qualifying studies met the inclusion criteria for language of instruction. Though the overall findings indicate a positive but modest effect (ES=+0.19) in favor of bilingual education, the largest and longest-term evaluations, including the only multiyear randomized evaluation of transition bilingual education, did not find any differences in outcomes by the end of elementary school for children who were either taught in Spanish and transitioned to English or taught only in English. The review also identified some proven and promising whole-school and whole-class interventions, including Success for All, cooperative learning, Direct Instruction, and ELLA. In addition, programs that use phonetic small group or one-to-one tutoring have also shown positive effects for struggling readers. What is in common across the most promising interventions is their use of extensive professional development, coaching, and cooperative learning. The findings support a conclusion increasingly being made by researchers and policy makers concerned with optimal outcomes for ELLs and other language minority students: Quality of instruction is more important than language of instruction. (Contains 2 tables and 1 footnote.) [For the "Effective Reading Programs for Spanish Dominant English Language Learners (ELLs) in the Elementary Grades: A Synthesis of Research. Educator's Summary," see ED539713.]