The border between Brazil and French Guiana is a place of economic, cultural, social and sexual exchange. Female sex workers represent a high risk population for HIV in this area where sexual tourism is particularly developed. HIV testing seems to be an important element in the fight against the epidemic. Indeed, early HIV testing gives access to treatments and prevention. An HIV/AIDS knowledge, attitudes, behaviors and practices survey was conducted in 2011 among sex workers along the border between Brazil and French Guiana. A total of 213 female sex workers were interviewed. One third (31.5%) of the interviewed had never tested for HIV. Factors associated with non HIV-testing were the lack of knowledge of places where to do an HIV test, to be 30 or older, feeling at risk of HIV, not evaluating one's own risk towards HIV, and living in Oiapoque. These results clearly suggest that targeted interventions are needed to encourage and assist female sex workers to get tested regularly.