More than 90% of all HIV infections in children result from mother to child transmission. Elimination of mother-child transmission is a global priority and vital for the improvement of child survival in high-burden, limited resource settings. Retention in HIV care is vital to reduce transmission risk. This qualitative study explored the experiences and adherence challenges of mothers living with HIV of the Prevention of Mother-to-Child Transmission of HIV (PMTCT) programme in Khayelitsha, Cape Town, South Africa. Interviews were conducted with purposively selected participants enrolled in a PMTCT programme at a primary care facility. Thematic analysis generated six themes. Findings demonstrate the complexity of living as a woman with HIV in a socioeconomically disadvantaged and marginalized periurban community. For each woman, there is a set of concerns relating to person, home, community, and clinic which may affect her understanding, acceptance of, and adherence to the PMTCT programme.