In endemic areas, due to the clinical signs of fever, enlarged spleen and liver, and reduction of white blood cells (less than 4000 white cells per cubic millimeter of blood), Kala azar disease is suggested.

Definitive diagnosis is only possible based on the direct observation of the parasite in the materials obtained from bone marrow aspiration, or lymph nodes after preparing the spread and staining method, as well as using a special culture medium or special serological tests.

The way to diagnose all three types of Leishmania is to see its parasite under a microscope. The visceral type of the disease can also be diagnosed through a blood test.