Vocabulary is one of the English components that needs to be mastered by the learners, yet most of the students have big problems in mastering vocabulary. Based on the researcher’s observation during PLP, it was found that at X and XI class had lack of vocabularies. The objectives of this research were to find out i) the significant improvement of students’ vocabulary mastery after being taught through short movie at the first grade of SMAN 15 Bandar Lampung and ii) the type of vocabulary which improves the most. The approach of this research was quantitative. There were 30 students of the first grade chosen. Vocabulary tests were used to collect the data. The researcher used a single group pretest-posttest design. The data were also computed by using SPSS 25.0 for Windows. The result showed that the mean of students’ vocabulary score was getting higher after the teacher utilized short movie, by having the number of 77.13. In addition, the gain of the test was 0.1832. It was found out that the students got higher enhancement in mastering the words of verb. The gain for this aspect was 0.25824. Besides, the mean of the tests were also increased from 6.3 in pretest to 7.3 in posttest. Keywords: vocabulary, vocabulary mastery, short movie