This study aimed to reveal the reasons and forms of bullying committed by male students to female students as well as understanding gender equality in senior high school students in the city of Mataram. This study employed a qualitative approach with a case study method. Data collection was done through interview, Focus Group Discussion (FGD), observation, and documentation. Data were analyzed qualitatively by triangulation (techniques and sources), reduction, display, and verification/conclusion. The results show that there was some bullying in senior high schools in Mataram. Many male students did bullying towards female students. They did bullying to female students in the form of physical, verbal, and nonverbal by using body movements, writing or pictures. They considered those bullying actions as joke and to show their power and strength to other students. The students have lack of understanding on gender equality. Male students dominated intra and extracurricular activities more than female students. Bullying, in the short term, can lead to the feelings of insecurity, isolation, low of self-esteem, depression, and suffering from stress. Due to the fact of many cases of bullying in schools, it is suggested, as the solution, to develop an antibullying policy and to apply gender equality education in order to stop or minimize the practice of bullying toward the female students in formal education environment.