Aim: To evaluate the prevalence of sexually transmitted infections (HIV, HBV, HCV, Treponema pallidum) in a cohort of foreign female sex workers observed in Palermo from 1999 to 2008., Materials and Methods: Authors conducted a prospective observational study on 239 foreign female sex workers aged between 18 and 36 years old. The nation of origin was Nigeria, Romania, Ucraina, Bulgaria., Results: Overall, the diagnosis of IST was placed in 17 women, 7.1% of the population under study. In 14 cases we observed a single infection: HIV in 5 cases; syphilis and HBV in 4 cases; HCV in only one case. In the remaining three women were diagnosed a co-infection with HIV and HBV, HIV and HCV, HIV and syphilis LUE. In our study, a statistically significant correlation (p<0.0001) was observed between the non-constant condom use and a higher frequency of HIV, HCV and syphilis infection. This correlation was not statistically significant in the women with HBV infection., Conclusions: The results of this study show a higher morbidity of this specific population, and, consequently, the need to start as soon as possible specific programs of intervention which can ensure the health of these women. Language and cultural barriers, as well as immigration concern among all vulnerable populations, form barriers to healthcare access.