The conceptualisation of male who have sex with male (MSM) to account for male homosexual behaviour has been developed to facilitate the endorsement of prevention message since the advent of HIV infection. Population studies performed to understand and monitor sexual and preventive behaviour usually recruit respondents through gay-friendly channels such as media, sexual venues or festivals, leading to recruitment bias. Few studies question possible differences according to varying sexual biography and current behaviour within the MSM population. The random sample of HIV+ individuals treated in specialised outpatient clinics (ANRS-EN12-VESPA study, 2003) provides the opportunity to question the MSM conceptualisation regarding sexual biography, social characteristics, current sexual behaviour, use of condom, living with HIV (quality of life, discrimination and participation in NGOs). Among the 2932 respondents, 1309 men reported a lifetime male sexual partner. Information regarding sexual biography (lifetime and current numbers of male and female sexual partners, lifetime number of male and female stable couples) was computed using cluster analysis and identified five profiles: exclusive gay (53.7%), gay with some bisexuality (21.8%), gay with mixed sexual history (8.1%), bisexual (7.8%) and heterosexual with male-to-male sex (8.6%). The profiles matched self-identification better among the most exclusive homosexuals than among men with current bisexuality. These five subgroups differed regarding demographic and social characteristics (except migration status), their period of diagnosis, age and CD4 count at diagnosis. Sexual activity, steady partnership, number of male and female partners, use of sexual venues and illegal substance use were different across subgroups. Reversely, these groups are homogenous regarding experience of discrimination and involvement in People living with HIV/AIDS (PLWHA) activities. These findings among men living with HIV support the MSM conceptualisation and underscore the role of medicine and HIV activism in shaping the experience of HIV infection.