HIV prevention strategies must be based on evidence of risk behaviours among people with HIV infection. This study aimed to determine the demographic, behavioural and self-reported disease/treatment variables that predict sexual risk behaviour, defined as unprotected intercourse with a partner of unknown or negative HIV status, among HIV-infected outpatients in Buenos Aires, Argentina. Two hundred consecutive outpatients (response rate 76.5%) participated in a self-complete cross sectional survey. The majority (49.5%) identified as heterosexual, and most were on antiretroviral therapy (ART) (75.5%). Undetectable viral load was currently achieved by 63%. Unprotected intercourse with a person of unknown or discordant status in the previous three months was reported by 20%. In multivariate analysis, risk was associated with lower distress from physical symptoms (p=0.012), greater distress from psychological symptoms (p=0.038) and being on treatment had borderline association with risk (p=0.058). The data reveal an important link between self-reported experience of disease, and treatment, with risk. Secondary prevention, care and treatment should not be conducted in isolation from each other if outcomes are to be optimised.