Two combretastatin heteroanalogues, called SAAS-41 and SAAS-59, were selected within a series of 44 compounds previously evaluated in vitro against Leishmania spp, and have now been assayed in vivo on BALB/c mice, infected with amastigotes of L. amazonensis. They were administered by three different routes. The most efficient compound, SAAS-59, administered subcutaneously (50 mg/kg), led to fair reductions of lesion size (-86.4%) and parasitic load (-97.4%), in percentages fairly higher than those observed for the reference drug glucantime at the dose of 100 mg/kg (-49.1% size; -60.1% load). Intralesional and oral administration of the product at the same dose, also induced significant decreases (-91.4% and -77.3% respectively) of the lesion size, but it did not show significant reductions of the parasitic load.