We investigated the feasibility of using mobile phone text messaging (SMS) to promote adherence to antiretroviral therapy among HIV-infected pregnant women recently diagnosed with HIV. Seven HIV-positive women (15–33 weeks gestation) from two urban antenatal clinics received mobile phones and were invited to use text messaging to discuss HIV, health and pregnancy over a 12-week period. All participants were connected to each other and to a clinician who guided the group and answered questions via group SMS messaging. A total of 1018 individual messages were sent regarding medical and psychosocial topics related to HIV and mother-to-child HIV transmission. Participants sent an average of 16 messages per enrolled, technology-problem-free week. Half the messages (51%) concerned medical information, and the remainder concerned social comments or addressed psychological matters. Four post-intervention interviews with participants revealed overall satisfaction and participants recommended that the group be offered in the future. The pilot project's anonymity, non-rigid nature and remote access allowed it to overcome stigma and logistical challenges where a conventional support intervention would probably have failed.