The current study analyzed existing data, collected under a previous U.S. Department of Education Reading First grant, to investigate the strength of the relationship between scores on the first- through third-grade Dynamic Indicators of Basic Early Literacy Skills - Oral Reading Fluency (DIBELS-ORF) test and scores on a reading comprehension test (TerraNova-Reading) administered at the conclusion of second- and third-grade. Participants were sixty-five English Language Learners (ELLs) learning to read in a school district adjacent to the U.S.-Mexico border. DIBELS-ORF and TerraNova-Reading scores were provided by the school district, which administers the assessments in accordance with state and federal mandates to monitor early literacy skill development. Bivariate correlation results indicate moderate-to-strong positive correlations between DIBELS-ORF scores and TerraNova-Reading performance that strengthened between grades one and three. Results suggest that the concurrent relationship between oral reading fluency scores and performance on standardized and high-stakes measures of reading comprehension may be different among ELLs as compared to non-ELLs during first- and second-grade. However, by third-grade the correlations approximate those reported in previous non-ELL studies. This study also examined whether the Peabody Picture Vocabulary Test (PPVT), a receptive vocabulary measure, could explain any additional variance on second- and third-grade TerraNova-Reading performance beyond that explained by the DIBELS-ORF. The PPVT was individually administered by researchers collecting data under a Reading First research grant prior to the current study. Receptive vocabulary was found to be a strong predictor of reading comprehension among ELLs, and largely overshadowed the predictive ability of the DIBELS-ORF during first-grade. Results suggest that receptive vocabulary scores, used in conjunction with the DIBELS-ORF, may be useful for identifying beginning ELL readers who are at risk for third-grade reading failure as early as first-grade.