Leishmaniasis is a neglected tropical disease with three main clinical manifestations. This disease is caused by protozoan parasites that are transmitted through the bite of female sandflies. Each year, more than one million cases of leishmaniasis are reported, and over one billion people are at risk of contacting the disease. Leishmaniasis is a complex disease that relapses when the immune system is suppressed. The currently available antileishmanial drugs have serious side effects. Therefore, it is important to identify novel drug candidates for leishmaniasis treatment. Phytochemicals are promising drug candidates because of their wide chemical diversity and bioavailability. This chapter provides an overview of leishmaniasis and highlights the phytochemicals that can be used to treat the disease.