Two studies of Grade 1 reading interventions for English-language (EL) learners at risk for reading problems were conducted. Two samples of EL students were randomly assigned to a treatment or untreated comparison group on the basis of their language of instruction for core reading (i.e., Spanish or English). In all, 91 students completed the English study (43 treatment and 48 comparison), and 80 students completed the Spanish study (35 treatment and 45 comparison). Treatment students received approximately 115 sessions of supplemental reading daily for 50 minutes in groups of 3 to 5. Findings from the English study revealed statistically significant differences in favor of treatment students on English measures of phonological awareness, word attack, word reading, and spelling (effect sizes of 0.35-0.42). Findings from the Spanish study revealed significant differences in favor of treatment students on Spanish measures of phonological awareness, letter-sound and letter-word identification, verbal analogies, word reading fluency, and spelling (effect sizes of 0.33-0.81).