We assessed the incidence and predictors of unprotected sex among 152 HIV-positive patients in clinical care in KwaZulu-Natal, South Africa. Nearly 50% were sexually active; 30% of those reported unprotected sex. Alcohol use during sex, reporting forced sex, sex with a perceived HIV-positive partner, and sex with a casual partner predicted more unprotected sex, whereas HIV status disclosure was related to less unprotected sex. These findings highlight the need for linking HIV prevention and care in Africa.