Because of taxonomic similarities to previous data found in the literature, and with the aim of improving treatment of toxoplasmosis, we considered it of interest to assay artemisinin, an effective anti-malarial agent, for the treatment of experimental infection in mice by Toxoplasma gondii. Different amounts of the anti-parasitic agent were administered, including after previous contact in vitro with toxoplasma and stimulated macrophage production. With the methodology used artemisinin was not effective. Suggestions for further studies are made.