This study examined university undergraduate English language learners' (ELLs) perspectives on an intervention, Word Matters, that aimed to enhance functional academic vocabulary learning critical to their cognitive academic language proficiency development (Cummins, 1989), a challenge faced by many ELLs in English-medium universities. This intervention provided undergraduate ELLs with instructional support of their vocabulary learning through the use of texting. It focused on their acquisition of academic and low-frequency words that appeared in the readings assigned by two content-based English for academic purposes (EAP) courses required for ELLs at a large Canadian university. The intervention was aligned with the lesson plans of the courses. Data in this study were collected from follow-up interviews (n = 10) and a post-treatment survey (n = 40) from a total of 48 students who participated in the intervention. The results revealed students' overall positive experience with the intervention, the feasibility of the intervention design and its effectiveness in supporting ELLs' vocabulary learning. The findings, students' suggestions for improving the intervention, and directions for future research are discussed.