BACKGROUND The study was carried out in a single township in South Africa with a sample size of seven human immunodeficiency virus (HIV)-serodiscordant couples. BACKGROUND South Africa has the highest number of HIV cases in the world, with an estimated 6.4 million of its inhabitants living with this infection. Most people in stable relationships are unaware of the HIV serostatuses of their partners. Many people with an HIV partner are also generally unaware of their own HIV serostatuses. There is a high risk of acquisition of the HIV among couples in HIV-serodiscordant relationships. Yet, there is a dearth of research on HIV-serodiscordant couples. OBJECTIVE To explore the experiences and knowledge of HIV-serodiscordant couples on HIV serodiscordance. METHODS A qualitative design of interpretative phenomenological analysis was used. Data were collected from seven HIV-serodiscordant couples using a semi-structured interview format. Data were analysed thematically using the principles of interpretative phenomenological analysis. RESULTS Three superordinate themes emerged from data analysis: experiences of stress, effects of HIV serodiscordance on couples and knowledge of HIV serodiscordance. The study outcomes were based on retrospective accounts of couples' experiences of HIV serodiscordance. Such accounts are subject to memory bias. CONCLUSIONS HIV-serodiscordant relationships are riddled with stress. Couples and nurses' knowledge and understanding of the concept of HIV serodiscordance is limited. Such limitation may negatively influence the quality of care and support offered to couples in these relationships. CONCLUSIONS HIV-serodiscordant couples need to be educated on this phenomenon. Nurses also need to be offered training on how to support and care for couples in these relationships. Such training should be shaped by couples' health-seeking behaviours and cultural norms. Specific guidelines and policy on HIV serodiscordance should be developed to ensure consistency in care provision and enhance uptake of support services.