Over the last decade, different cross-sectional and case-control studies have shown the relationship between HIV and Sexually Transmitted infections (STI). In this sense, different reasons are found: a modification of the clinical manifestations of some STI as well as an increase of HIV infectiousness and susceptibility to HIV. The main objective of HIV/AIDS and STI surveillance includes: to assess its temporal trends, to define high risk groups and high-risk behaviours and to plan and to evaluate public health programmes. Nevertheless, classical surveillance systems are not enough to describe the real situation of HIV/AIDS and STI. Thus, an enhanced surveillance system which includes complementary resources should be implemented.