English language learners (ELLs) lack academic vocabulary knowledge, an essential component that explains much of the persistent achievement gap between students who start schools as ELLs and their monolingual peers. This single-subject experimental design study addressed this issue by focusing on self-regulated vocabulary learning that helps ELLs become effective and independent word learners. Nine upper elementary ELLs participated in an intervention for 16 sessions, with about 35 minutes per session. The intervention included the instruction of task-specific cognitive strategies (i.e., morphological and contextual analyses) and metacognitive strategies (i.e., goal-setting and monitoring) in authentic reading texts in social studies. Results indicated positive effects on ELLs' vocabulary knowledge and self-­regulated vocabulary learning skills. Participants were also able to generalize both cognitive and metacognitive strategies to learning of new words. A lagging effect was observed for participants with low English proficiency levels.