National audience. This article questions the issues of visibility and invisibility in the construction of socio-political categories. By mirroring the battle of black against racism and that of HIV/AIDS patients against the epidemic, we promote the idea that the socio-political minority groups shape and maintain themselves in a seemingly paradoxical fight for visibility. Based on Goffman’s traditional definition of stigma, this comparison seeks to measure the effects of an ‘obvious’ social marker such as skin colour, or hidden, such as disease, on records of collective mobilisation. We put in perspective the importance of this distinction, suggesting that the two groups should have one and the same battle for their recognition as a social minority, and by arguing that the success of this struggle depends on their visibility in the social sphere. People living with HIV must invent their visibility, but in a social world that tends to stigmatise their ‘deviating’ practices, while black people have to reinvest an existing racial category, but to subvert borders and senses. This visibility of the group and its suffering may entail the risk of further stigmatisation, but this risk is accepted as the category created is a category of fight: it is used to call for a public intervention that ultimately takes responsibility for the destruction of stigma, taking the category with it.