Mobile phones have the potential to improve access to healthcare information and services in low-resourced settings. This study investigated the use of mobile phones among patients with chronic diseases, pregnant women, and health workers to enhance primary healthcare in rural South Africa. Qualitative research was undertaken in Mpumalanga in 2014. Semi structured in-depth interviews were conducted with 113 patients and 43 health workers from seven primary healthcare clinics and one district hospital. Data were thematically analysed. We found that some health workers and patients used their own mobile phones for healthcare, bearing the cost themselves. Patients used their mobile phones to remind themselves to take medication or attend their clinic visits, and they appreciated receiving voice call reminders. Some patients and health workers accessed websites and used social media to gather health information, but lacked web search strategies. The use of the websites and social media was intermittent due to lack of financial ability to afford airtime among these patients and health workers. Many did not know what to search for and where to search. Doctors have developed their own informal mobile health solutions in response to their work needs and lack of resources due to their rurality. Physical and social factors influence the usability of mobile phones for healthcare, and this can shape communication patterns such as poor eyesight. The bottom-up use of mobile phones has been evolving to fill the gaps to augment primary care services in South Africa; however, barriers to access remain, such as poor digital infrastructure and low digital literacy.