Computer-assisted language learning (CALL) and mobile-assisted language learning (MALL) approaches have had positive effects on language education. Quizlet is an emerging tool which has helped many language learners to achieve their learning goals. The study aims to explore students’ perceptions on the use of Quizlet for their learning vocabulary. Both quantitative and qualitative approaches were employed to examine the frequency of use among students and their level of satisfaction toward Quizlet as well as its advantages and disadvantages it brought students. For data analysis, 148 students participated in the study through a questionnaire and a semi-structured interview. The results revealed that students sometimes used Quizlet for their learning vocabulary (M=3.073, SD=.6485) with the frequency of approximately 2 hours per week. In addition, students’ level of satisfaction was rated quite positive (M=3.515, SD=.8289). In particular, the feature Test was most noticeable and satisfactory since it helped students review vocabulary effectively. Many students preferred Quizlet because of its convenience and effectiveness while others were dissatisfied with some features such as Match as well as some spelling and definition errors, and unnatural pronunciation. It is to suggest that students would prefer Quizlet as a helpful tool for their vocabulary mastery. Besides, Quizlet developers could upgrade its features to make it an outstanding aid for language learners.