This study aims to determine whether there is a difference in students’ vocabulary mastery between the use of the role-playing method and the conventional method and if the use of role-playing method can increase students vocabulary mastery at SMPN 4 Majene. The approach used in this study is quantitative and the research design is a quasi-experimental method. The research sample consisted of two classes, namely the experimental class using the roleplaying method and the control class using the conventional method. Data were collected through a vocabulary mastery test given before (pre-test) and after (posttest) the treatment. The results of the study showed that the average pre-test score of the experimental class was 68.77 and the post-test was 77.59, while the average pre-test score of the control class was 64.64 and the post-test was 69.86. Based on the results of the independent sample t-test, a significance value of 0.007 <0.05
was obtained, which indicates that there was a significant increase in vocabulary mastery in the experimental class. The results of the paired sample t-test showed a significance value of 0.000<0.05, which indicates that there is a significant difference between the experimental class and the control class. This means that the method can be applied to increase students’ vocabulary mastery.