Visceral leishmaniasis is categorized as a neglected tropical disease (NTD) and represents critical public health issue in less developed countries. It is also known as kala-azar, or black sickness in Hindi, because it can lead to black or gray discoloration of the skin. Due to the fact that untreated cases result in a mortality rate of over 95%, treating the disease is a necessity. Another important issue is the dermal sequela of the disease called post-kala-azar dermal leishmaniasis. After being cured of visceral leishmaniasis, dermal symptoms may develop, with an onset ranging from several months to a few years. It is still not clear whether this occurs as a result of persistent parasites or reinfection, but patients with this form of the disease represent an important source of infection and consequently complicating efforts to eliminate the disease. Moreover, rises in HIV-VL co-infection are being recorded, recognizible by frequent relapses and a poor outcome to treatment. Although meaningful progress has been made in some countries in controlling the disease, climate change, poverty, and numerous migrations favor the survival of Leishmania spp., further efforts are needed in order to stop the spreading of the disease and for gaining control over the disease in endemic countries.