HIV infection natural history is extremely changed, today. When we observed HIV virus infection for the first time in 80’s, this was a dramatic diagnosis and people were frightened by patients affected. This behaviour explained the great diffusion of HIV infection in the past time and the usefulness of prevention strategy. Instead of, in the last two decades, global prevention strategies explained how the infection could be transmitted and they reduced the HIV seropositive patient’s stigma. In 90’s, the HIV infection turned from a lethal pathology into a chronic infection. In that period infact, we learn how mixed together some old and new drugs, that combined became HAART, the first strongly active HIV therapy. Nowadays, the HIV infection is considered as a chronic one. In 2014, there were 35.000.000 patients living with HIV infection in the world. More than 40.000.000 persons died in the world during this epidemic disease. In the past, the virus transmission was especially related to parenteral transmission, intravenous drug use and homosexual behaviours. Today, the most important way of transmission is the sexual one. The reduction of viral transmission in intravenous drug users population is obviously related to a great prevention work by specialized services, who take care of that kind of patients (Servizio per le Dipendenze Patologiche: Ser.D). In the last two decades, we observed a reduction of the new HIV seroconversions and of the AIDS related deaths. The HAART therapy is now available also in the poorest parts of the world, like Africa, for example. WHO encourages all the Countries to defeat HIV infection at least in 2030, but this project seems to be an utopic one.