Protein synthesis has been a very rich target for developing classes of drugs to control prokaryotic and eukaryotic pathogens. Despite the development of new drug formulations, treating human cutaneous and visceral Leishmaniasis still needs significant improvement due to considerable side effects and low adherence to the usual treatment regimen. In this work, we show that the di-substituted urea-derived compound I-17 is effective in inhibiting the promastigote forms and intracellular amastigotes of the Leishmania (L.) amazonensis and L. infantum species, in addition to exhibiting low macrophage cytotoxicity. We also show a potential immunomodulatory effect of I-17 in infected macrophages, which exhibited increased expression of inducible Nitric Oxide Synthase (NOS2) and Nitric Oxide (NO) production. Our data suggest that I-17 and new derivatives of this compound may be helpful in developing new drugs for treating leishmaniasis.