This study seeks to explore acculturation of Muslim youth in the Netherlands, with a focus on boundary maintenance between the sexes. For this purpose, it examines the values and norms Muslim youth are taught and socialized into on this subject at mosques in the Netherlands, which are then compared with those conveyed at secondary schools. Findings based on 62 in-depth interviews with secondary school students and young adults from four Muslim communities (Turkish, Moroccan, Pakistani and Egyptian) revealed that Muslim youth received conflicting messages and were socialized into contradictory norms in these two learning contexts. While sex segregation was observed in many mosques’ educational programs, the mainstream schools were coeducational. Moreover, the mosques’ narrative and hidden curriculum entailed an Islamic ethos requiring physical and social distancing between the sexes, avoiding male gaze, and refraining from physical touch. Yet, at schools, boys and girls were expected to work in groups, interact, discuss, and socialize, and handshaking with teachers before lessons was observed at some schools as a ritual symbolizing respect. Furthermore, the study considered the ways in which Muslim youth navigated these contradictory values, using their individual and collective agency in diverse contexts. Their acculturation strategies included accommodation, frame switching, mediation, resistance, and social control. The findings have implications for the social integration, mental health and well-being of Muslim youth.