Visceral Leishmaniasis is a vector-borne parasitic infection caused by a parasite of the genus Leishmania. This disease, which is more frequent between children than adults, knew during these last few years in Morocco a significant surge especially in the region of Fez. The direct examination, based on the detection of the parasite or its nucleic acid, is undoubtedly the key to a definite diagnosis, along with serological techniques that were proven to be efficient and could also aid the diagnosis. This study highlights the benefit of rK39 rapid tests in visceral Leishmaniasis diagnosis through the retrospective of 75 patients suspected to have Visceral Leishmaniasis. We shall also compare our results with those of other authors in different countries.