Leishmaniasis is one of the most important parasitic infections, but current treatments are unsatisfactory due to their toxicity, cost and resistance. Therefore, the development of new antileishmanial compounds is imperative. Many people who live in endemic areas use plants as an alternative to treat the disease. In this paper, we characterised the essential oil from
Piper auritum
, evaluated its cytotoxicity and determined its antileishmanial activity. The chromatogram obtained by gas chromatography revealed 60 peaks and we found that safrole was the most abundant compound, composing 87% of the oil. The oil was active against the promastigotes of
Leishmania major
,
Leishmania mexicana
,
Leishmania braziliensis
and
Leishmania donovani
with a favourable selectivity index against peritoneal macrophages from BALB/c mice. The Piper-oil inhibited the growing of intracellular amastigotes of
L. donovani with an IC50 value of 22.3 ± 1.8 μ/mL. This study demonstrates the usefulness of the essential oils as a promising alternative to treat leishmaniasis.
