SMSaúde is a multisite randomised clinical trial of HIV-infected adults on ART and HIV-infected pregnant women in six clinics in Maputo Province, Mozambique. Eligibility criteria include: currently residing in the province; no plans to move for 12+ months; have own cell-phone; literate; 8-28 weeks pregnant (PMTCT cohort); on first line ART and on ART for >15 days (ART cohort). Patients were interviewed for eligibility, and then randomized (1:1). SMS reminders are sent to the intervention group using software that picks up the patient's next appointment from the electronic patient database. Primary outcomes tested were improved retention in ART care and uptake of all PMTCT services.