It is unclear whether higher rates of sexual partner concurrency in Black South Africans are due to socioeconomic or cultural factors. We used a nationally representative sample of 9,728 individuals aged 16 to 55 from a study conducted in 2009 to examine how the norms pertaining to concurrency and the practice of concurrency vary by race, class, and gender. The percentage of men reporting point concurrency was 14%, 6.5%, and 2.5% in Blacks, coloreds, and Whites, respectively (p < 0.001). These percentages increased to 45.7%, 24.7%, and 11.7%, respectively, for those reporting lifetime concurrency (p < 0.001). In all the racial groups, men exhibited more favorable attitudes toward concurrency than women did. For a range of indicators, White men and women had less favorable attitudes toward concurrency than Black men and women. These differences remained after controlling for a range of confounding variables. In the adjusted logistic regression model, reported concurrency in men was associated with a younger age, Black race, being in the lowest income tertile, not being in a stable relationship, and expressing various positive attitudes toward concurrency.