Male prisons typify any social situation where individuals interact with others, learn to cope and survive, and contend with normative conventions and expectations. Being compulsory, prison can be an intense social experience that challenges emotional, psychological and social health and wellbeing, exacerbating individuals’ efforts to acquire social legitimacy and status. Social survival is paramount, even if this compromises health, wellbeing and longer term rehabilitation, as prisoners and prison staff engage in self-censorship, self-subjectification and objectification. Deference to the hegemonic masculine institutional culture is played out via prison masculinities that reflect normative social and institutional values evident in attitudes, behaviours and regime processes. This chapter draws upon ethnographic research conducted with male prisoners to illustrate how masculinities are enacted, sanctioned and condoned at individual and institutional levels, consistent with historical conventions of gender, power and discipline.