The purpose of this study was to understand relationships between English proficiency and academic performance for a group of English language learners (ELLs) from 4 elementary schools. Descriptive and inferential statistics were used to examine scores from the Language Assessment Scales, the Woodcock-Munoz Language Survey, and the Colorado Student Assessment Program. Findings showed that English proficiency was significantly related to English academic achievement, even for ELL students who had been in U.S. schools for 3 years or longer. Furthermore, the 5th-grade ELL cohort had greater increases in reading and writing scores compared to all Colorado 5th graders. This led to a slight closing of the achievement gap. Lastly, Spanish achievement, especially when combined with English proficiency, predicted English achievement. (Contains 7 tables and 1 endnote.)