Although HIV-related stigma in general is known to deter HIV-testing, the extent to which different dimensions of stigma independently influence testing behaviour is poorly understood. We used data on young black men (n = 553) and women (n = 674) from the 2009 Cape Area Panel Study to examine the independent effects of stigmatising attitudes, perceived stigma and observed enacted stigma on HIV-testing. Multivariate logistic regression models showed that stigma had a strong relationship with HIV-testing among women, but not men. Women who held stigmatising attitudes were more likely to have been tested (OR 3, p < 0.01), while perceived stigma (OR 0.61, p < 0.1) and observed enacted stigma (OR 0.42, p < 0.01) reduced the odds significantly of women having had an HIV test. Our findings highlight that different dimensions of stigma may have opposite effects on HIV testing, and point towards the need for interventions that limit the impact of enacted and perceived stigma on HIV-testing among women.