This study determined the perception of sex workers in the city of Monteria, Cordoba (Colombia) against the risks associated with sexually transmitted infections. It is a qualitative study whose sample was composed of 44 sex workers who work in establishments the city of Monteria. The data were obtained by applying a Likert scale focus group. Sex workers do not fully believe that the condom is a good method for preventing STIs, therefore do not consider it a good investment, they are afraid of becoming infected with an STI, but they perceived their income to pay current expenses generated by an STI. Beliefs and representations predominate in the adoption of high-risk behaviors. It requires more psycho-social and raising awareness of STIs.