The purpose of this study was to examine whether technology- based learning environments have the potential to support dual-language learners' (DLLs) vocabulary learning in their less dominant language. Interrogating Dual-Coding Theory (Paivio, 1986), this study investigates whether DLLs benefit from media content that is delivered both orally and visually, and uses English language proficiency as an important contextual factor that might impact vocabulary learning on screens. Adopting a within-subjects design on 43 preschool-aged DLLs, and using eye-tracking technology to monitor children's attention, this study finds that DLLs are able to identify more words that are taught on screen when information is dual-coded, particularly if they have lower English language proficiency. Implications for the field of computer-assisted language learning are discussed. [This is the online version of an article published in "Computer Assisted Language Learning."]