Abstract: Use of simple acyclic polyamines for the treatment of parasites of the family Trypanosomatidae The present invention provides the use of certain single acyclic polyamines of Formula (I), attached to heterocycles, for the treatment of leishmaniasis and trypanosomiasis. All the compounds studied show antiparasitic activity against Leishmania species, comparable or superior to that of the active ingredient of the drug commonly used to treat this disease, but with a macrophage toxicity similar to or, in most cases, lower than that of the commercial reference compound, and with higher selectivity indices against strains representative of the three clinical forms of the disease: cutaneous, mucocutaneous and visceral. The compounds show ability to inhibit parasite superoxide dismutase, generally at concentrations lower than those required to inhibit human superoxide dismutase. All this supports its usefulness for treating leishmaniasis and also trypanosomiasis.