Drawing from theory and research on the role of social networks in promoting or undermining preventative public health measures, this article considers how structural, compositional and functional aspects of older adults’ close social networks are associated with HIV testing in the context of rural South Africa. Analyses use data from the population-based Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) – a sample of rural adults age 40+ (N = 4,660). Results from multiple logistic regression show older South African adults with larger, more heavily non-kin and more literate networks were most likely to report testing for HIV. People whose network members provided frequent information were also most likely to be tested, though interaction effects indicate that this pattern is primarily found among those with highly literate networks. Taken together, the findings reinforce a key insight from social capital perspectives: network resourcefulness – literacy in particular – is crucial for promoting preventative health practice. The synergy between network literacy and informational support reveals the complex interplay between network characteristics in shaping health-seeking behaviour. Continued research is needed on the connection between networks and HIV testing among sub-Saharan older adults, as this population is not currently well served by many public health efforts in the region.