Cases of visceral leishmaniasis (VL) in HIV-positive individuals have been reported from most areas of the world where the geographical distributions of the two infections overlap. The majority of the co-infected cases that have been recorded, however, live around the Mediterranean basin. In these subjects, the length of the incubation period of VL is presumably very short, particularly in those who have severe immunodepression. At diagnosis, almost all cases of VL/HIV co-infection have been found to have fewer than 200 CD4+ cells/microl blood, and about 50% meet the AIDS-defining criteria during their first episode of VL. The clinical manifestations of VL in HIV-infected individuals may be similar to those seen in HIV-negative cases; fever, pancytopenia and hepato-splenomegaly, for example, are found in 75% of all the HIV-positive cases. Following the dissemination of the parasites, however, the HIV-positive cases may develop unusual, multi-organ pathology. Almost all the cases of co-infection are very prone to VL relapses, even after carefully managed antileishmanial treatment. The opportunistic infections that are often seen in HIV-positives frequently develop during VL episodes, the signs and symptoms of the leishmaniasis then confusingly overlapping with those of the other infections.