The use of technology cannot be separated from human life. No wonder the world of education also utilizes technology in its practice, such as English learning. The use of technology in learning is related to the use of smartphones, computers, laptops, and other applications. Language learning that utilizes mobile-based technology is included in Mobile-Assisted Language Learning (MALL) scope. Vocabulary as the basic skill to master the four skills in English plays an important role because it would be difficult to learn English without vocabulary knowledge. Considering the importance of vocabulary in English learning, this study was conducted to find out students’ perceptions on the use of Mobile-Assisted Language Learning (MALL) in learning English vocabulary and students’ reasons in using MALL in learning English vocabulary. The scope of this research focused on the use of mobile applications as mobile devices in MALL. This research was a descriptive study and used a survey as the research method. The participants of this study were 35 students. There were two kinds of the questionnaire in data collection, closed and opened questionnaires. The result of the questionnaire described that students have the positive perception on the use of MALL in learning English vocabulary. This is supported by the statement such as they enjoy learning using mobile applications and the students were more motivated in learning English vocabulary using the mobile application because the mobile application is completed with the features to pronounce and easy to access every time and everywhere. Besides, there were several students’ reasons in using Mobile-Assisted Language Learning (MALL) and most students’ reasons are: easy to use, simple to find the new vocabulary; easy to access in every time and everywhere (flexible). It can be concluded that students’ perception on the use of Mobile-Assisted Language Learning (MALL) in learning English vocabulary was considered to be useful and help their learning.