Visceral Leishmaniasis is an endemic infection in Portugal, as well as in other Mediterranean basin countries, where it has become a frequent complication of HIV infection. There are several studies published about Leishmania/HIV co-infection, however some particularities of its epidemiology, pathogenesis and especially of its treatment and prophylaxis remain unclear and undefined. The authors review some aspects of this co-infection, particularly epidemiology, clinical classic manifestations and laboratory features, diagnosis, treatment, prophylaxis and prevention and report the casuistic of the Infectious Diseases Department of the University Hospital of Coimbra during the last ten years (1996-2006) in the HAART (<<highly active antiretroviral therapy>>) era. Visceral Leishmaniasis behaves as an opportunistic infection in HIV-infected patients and should be considered as an AIDS-defining disease. Nowadays and according to World Health Organization, VL is the second most important protozoan disease and one of the most neglected; therefore the establishment of treatment and prophylaxis guidelines is urgent.