This study explores the role of gender as a central organizing principle in the inclusion work within martial arts clubs in Sweden, against a backdrop of inclusion being an explicit focus in the policy programs of the sports movement. Based on qualitative data collected through focus group interviews with representatives from three martial arts clubs, this study departs from a social constructionist perspective where gender is understood as a social process or a ‘doing’. The analysis of the data reveals two distinct approaches to gender as an organizing principle: downplaying the significance of gender and explicating the significance of gender. Within the first approach the meaning and significance of gender are subordinated by organizing mixed-gender groups and regulating interactions within the groups. The importance of equalizing potential physical differences and avoiding sexism in practice, is emphasized. However, the approach also brings forward challenging situations related to gender and other inclusion aspects, such as religious beliefs and cultural backgrounds. The second approach recognizes the significance of gender as a structural aspect and employs gender-separatist training groups and specific activities for girls and women. These targeted efforts are justified by the respondents because of the male dominance and masculinity norms that exist in martial arts and hinder girls’ and women's participation. The findings highlight the complexities and tensions of how gender is constructed and reproduced within the context of martial arts clubs and contribute to deepening the understanding of how these constructions condition the inclusion work.