The background of this research is that there have been many dishonesty cases that happen among students, such as cheating, play truant, and even rules violations. The implementation of honesty character building strategy is expected to turn the students’ negative behaviors into the good ones. There are three objectives of this research: 1) to analyze the strategy of honesty character building towards the grade VII students of SMP IT Masjid Syuhada Yogyakarta, 2) to describe the effect of the implemented strategy in building the honesty character towards the grade VII students of SMP IT Masjid Syuhada Yogyakarta, 3) to describe the supporting and inhibiting factors of the honesty character building towards the grade VII students of SMP IT Masjid Syuhada Yogyakarta. This research used descriptive-qualitative approach. The location was in SMP IT Masjid Syuhada Yogyakarta. The data collection technique was through observation, interview and documentation. The data analysis was through data reduction, data presentation and conclusion drawing. The research result shows that the strategy of honesty character building towards the grade VII students of SMP IT Masjid Syuhada Yogyakarta is through: 1) learning and teaching activities, 2) homeroom teachers’ development, 3) exemplary, 4) rules and regulations obedience, and 5) CCTV surveillance. The effects of this strategy are: 1) the students’ increasing awareness of honesty character, 2) the students’ anxiety to break the rules, 3) the student’s increasing awareness to self-behave, 4) the students’ increasing courage to express opinions, 5) the students’ improvement in doing prayers discipline. Meanwhile, the supporting factors of the honesty character building towards the grade VII students are: 1) parents’ role, 2) the existing rules and regulations, 3) curriculum development, 4) homeroom teachers’ development, 5) CCTV surveillance. The inhibiting factors are: 1) the students themselves, 2) friends/environment, 3) unaccomplished programs, and 4) lack of creativity.