This study was a classroom action research. It was for improving students’ vocabulary of the second grade of Madrasah Tsanawiyah (MTS) in Cilongok, Central Java, Indonesia, in the academic year 2017/2018 through suggestopedia method. There were pre cycle, cycle 1 and cycle 2. This reseach was conducted in May 2018 at MTS and it involved twenty five students as the respondents. The instruments in this research were observation sheets, questionnaire, interview and test. Based on the result, the implementation of suggestopedia method in vocabulary mastery had shown an improvement. In the result of test in 2nd cycle, 100% students passed minimum passing grade criteria. Moreover, the students’ perception towards suggestopedia were positive. It showed that the mean of pre questionnaire 32.2% and the post questionnaire 88.8%. In addition, the implementation of suggestopedia method was able to improve the students’ interest, enjoyment and motivation toward the teaching learning process. Based on these findings, it could be concluded that the implementation of suggestopedia method improved students’ vocabulary.