Women in sub-Saharan Africa are increasingly learning their HIV status in prevention of mother-to-child transmission of HIV (PMTCT) programmes in the context of antenatal care. This paper examines women's decisions about HIV testing and their experience of PMTCT and HIV-related care in one clinic in Lilongwe, Malawi. It is based on qualitative, ethnographic research conducted in 2004 and 2005, including interviews and focus group discussions with 55 HIV-positive women participating in a PMTCT programme, and 21 interviews with key informants from the programme and the health system. Women's expectations from testing were consistent with the benefits for their own health and their infants' health, as communicated by nurses. However, the PMTCT programme only poorly met their expectations. Reasons for this disjuncture included the construction of women as still healthy even when they needed treatment, a focus only on infant health, health system weaknesses, lack of integrated care and timely referral, and defining HIV exclusively as a medical issue, while ignoring the social determinants of health. Women's own health was particularly marginalised within the PMTCT programme, yet good models exist for comprehensive care for women, infants and their families that should be implemented as testing is scaled up.