Leishmaniasis is endemic worldwide with more than 2 million new cases reported every year. The disease is caused by a protozoan parasite of the genus Leishmania, and is transmitted by the bite of sand flies. Depending on the Leishmania species, the disease can have many outcomes, ranging from localized or diffuse skin lesions, destruction of the nasal septum and mouth palate, and in its most severe form, visceral leishmaniasis where there is extensive involvement of internal organs. Localized cutaneous leishmaniasis is the least severe form of disease and is characterized by a protective immune response. The more damaging forms are accompanied by poor immune responses that allow uncontrolled spread of the parasite – these forms can be fatal if left untreated. Treatments vary and depend on the type of disease and Leishmania species, but all have side effects and some are quite toxic.