The high demand on the mobile devices like smart phones and ipads in daily life has given a rise to mobile learning trends in second or foreign language learning. The main purpose of this study was to investigate the differences in vocabulary achievement level of students keeping mobile-based and paper-based vocabulary notebooks in English language learning. The study was designed through a mixed method where a pre-post test control group quasi-experimental study was conducted. Data were collected through a vocabulary achievement test used as pre and post tests. The results indicated mobile-based vocabulary notebooks have positive effects on students' vocabulary achievement.