Visceral leishmaniosis is one of the most fatal old-world neglected disease with estimated 90 thousand worldwide cases emerge each year. In Iraq, the cutaneous and visceral form are endemic but available chemotherapies are either toxic with diverse side effects, expensive available drugs or parasite resistant is arising. Artemisinin (ART) is a semi-synthetic compound which proved its effectiveness against protozoan parasites, such as malaria and Leishmania. In this study, the efficacy of different concentrations of pure artemisinin was screened in vitro against promastigotes and axenic amastigotes by MTT assay after 24, 48 and 27 hours follow up. In addition, the infectivity ability and number was investigated of intra-cellular Leishman bodies in treated murine peritoneal macrophages after 24 and 48 hours ART treatment. The results verified ART efficacy against the promastigotes and axenic amastigotes viability with IC50 measured after 24, 48- and 72-hours treatment. Infectivity percentage of murine macrophages and parasite burden were significantly reduced in treated cells. These findings indicate the leishmanicidal activity of ART against the Iraqi isolate of L. donovani and further in vivo study is recommended for assigning ART as a natural anti visceral leishmaniosis compound.