The article explores the idea of therapeutic citizenship in relation to the experiences of men who attend support groups for people living with HIV or AIDS (PLHIV). At a rural South African health facility offering free antiretroviral (ARV) medicines, support groups aim to empower HIV-positive clients through knowledge and skills that enable them to adhere to their ARV regimen. Members are exhorted to abandon their 'traditional' health and gender beliefs in favour of a biomedical understanding and approach to health; to embrace participation in a support group for PLHIV; and to actively challenge HIV stigma through the public disclosure of their HIV-test result. Fourteen months of ethnographic fieldwork conducted in Bushbuckridge, Mpumalanga Province, South Africa, investigated how men negotiated these efforts - normally characterised in the academic literature as 'therapeutic citizenship' - in relation to men's socio-cultural definitions of masculinity. The findings reveal that most of the men gained the knowledge and skills necessary to adhere to treatment. Although they generally behaved in a disciplined way, they remained doubtful about their commitment to the particular kind of 'HIV identity' that a support group conferred on them. Men who embrace this identity must abandon their previous masculine lifestyles and conform to the support group's messages concerning what it means to be a 'responsible' HIV patient. The research documents some of the challenges men experience in negotiating these conflicting demands. The discussion draws on personal accounts by the participants to illustrate the ambivalence of men towards their 'HIV identity' and to belonging to a support group.