Background: Mobile health (mHealth) is a promising tool to deliver healthcare interventions to underserved populations. We characterized the use of mobile devices in rural KwaZulu-Natal, South Africa to tailor mHealth interventions for people living with HIV and at risk for acquiring HIV in the middle-income country. Methods: We surveyed participants in community settings and offered free HIV counseling and testing. Participants selfreported their gender, age, relationship, and employment status, receipt of monthly grant, condomless sex frequency, and circumcision status (if male). Outcomes included cell phone and smartphone ownership, private data access, health information seeking, and willingness to receive healthcare messages. We performed multivariable logistic regression to assess the relationship between demographic factors and outcomes. Results: Although only 10% of the 788 individuals surveyed used the phone to seek health information, 93% of cell phone owners were willing to receive healthcare messages. Being young, female, employed, and in a relationship were associated with cell phone ownership. Smartphone owners were more likely to be young, female, and employed. Participants reporting condomless sex or lack of circumcision were significantly less likely to have private data access or to purchase data. Conclusions: mHealth interventions should be feasible in rural KwaZulu-Natal, though differ by gender. As women are more likely to own smartphones, smartphone-based mHealth interventions specifically geared to prevent the acquisition of or to support the care of HIV in young women in KwaZulu-Natal may be feasible. mHealth interventions encouraging condom use and medical male circumcision should consider the use of nonsmartphone short message service and be attuned to mobile data limitations-especially when targeting men.