Support to health programming has increasingly placed an emphasis on health systems strengthening. Integration of prevention of mother-to-child transmission (PMTCT) and maternal and newborn child health (MNCH) services has been one of the areas where there has been a shift from a siloed to a more integrated approach. The scale-up of anti-retroviral therapy has made services increasingly available while also bringing them closer to those in need. However, addressing supply side issues around the availability and quality of care at the health centre level alone cannot guarantee better results without a more explicit focus on access issues. Access to PMTCT care and treatment services is affected by a number of barriers which influence decisions of women to seek care. This paper reviews published qualitative and quantitative studies that look at demand side barriers to PMTCT services and proposes a categorisation of these barriers. It notes that access to PMTCT services as well as eventual uptake and retention in PMTCT care starts with access to MNCH in general. While poverty often prevents women, regardless of HIV status, from accessing MNCH services, women living with HIV who are in need of PMTCT services face an additional set of PMTCT barriers. This review proposes four categories of barriers to accessing PMTCT: social norms and knowledge, socioeconomic status, physiological status and psychological conditions. Social norms and knowledge and socioeconomic status stand out. Transport is the most frequently mentioned socioeconomic barrier. With regard to social norms and knowledge, non-disclosure, stigma and partner relations are the most commonly cited barriers. Some studies also cite physiological barriers. Barriers related to social norms and knowledge, socioeconomic status and physiology can all be affected by the mental and psychological state of the individual to create a psychological barrier to access. Increased coverage and uptake of PMTCT services can be achieved if policy makers and programme managers better understand the barriers that may prevent their potential target population from taking up and adhering to their services. The categorisation presented in this review provides further insight into the type of barriers that may exist