Leishmaniasis is a clinically heterogeneous syndrome caused by intracellular 
protozoan parasites of the genus Leishmania. The clinical spectrum of 
leishmaniasis encompasses subclinical (not apparent), localized (skin lesion), 
and disseminated (cutaneous, mucocutaneous, and visceral) infection. This 
spectrum of manifestations depends on the immune status of the host, on the 
parasite, and on immunoinflammatory responses. Visceral leishmaniasis causes 
high morbidity and mortality in the developing world. Reliable laboratory 
methods become mandatory for accurate diagnosis, especially in immunocompromised 
patients such as those infected with HIV. In this article, we review the current 
state of the diagnostic tools for leishmaniasis, especially  the serological 
test.