Despite the availability of HIV testing and counselling in antenatal care clinic settings, many HIV infected mothers in sub-Saharan Africa give birth in health facilities without knowledge of their own HIV status, thereby missing an opportunity to prevent the vertical transmission of HIV to their infants and to care for their own health. The study identifies system-related, social and behavioural reasons that pregnant women present themselves at labour wards with unknown HIV status and do not receive testing and counselling, either during labour or following delivery. Using primarily qualitative methods, a descriptive study was conducted in two districts in southern Malawi.The barriers identified in the study compelled women to refuse testing, hide results or develop strategies to keep their HIV status unknown or undisclosed. Understanding the dynamics and cultural boundaries that limit women’s access to testing is essential to improving this gateway to prevention of mother-to-child transmission care.