A qualitative study was conducted with 28 men and women in HIV-serodiscordant couples to explore the management of HIV in their relationship. Content analysis of the interviews revealed the role of serostatus and stigma in shaping partners' experience of HIV, sex and risk. Partners' differing serostatus often created feelings of alienation within the relationship. Compounding this interpersonal dynamic, the HIV service community was experienced as segregating because they were not funded or prepared to work with seronegative partners. Thus many, particularly seronegative women, felt invisible both within and outside of the relationship. Yet, the uninfected partners shared the burden of a stigmatizing illness because of the serodiscordant relationship. Stigma hindered communication about HIV and sex, disclosure to others and access to services. Many experienced HIV as a loss of their sexuality. Seronegative partners spoke about 'keeping sex alive' and often had to push to continue having sex. Couples used multiple strategies to manage HIV, including developing strict behavioural guidelines, connecting with other couples, accessing scientific information and becoming educators and activists. These altruistic activities, which also included participation in research, helped to transcend external and internalized stigma. Implications for developing interventions for HIV-serodiscordant couples are discussed.