In this paper is described the obtention of fourteen derivatives from four natural labdane diterpenes isolated from Copaifera oleoresin, named ent-copalic acid (1), ¬ent-3beta-acetoxy copalic acid (2), ent-3beta-hydroxy copalic acid (3) and ent-agathic acid (4). All eighteen compounds were assayed against promastigote form of Leishmania amazonensis and trypomastigote forms of Trypanosoma cruzi, revealing two promising compounds related to leishmanicidal activity (IC50 = 5.94 micromolar and 5.31 micromolar) and three promising compounds with trypanocidal activity, two of them (IC50 = 13.31micromolar and IC50 = 15.05micromolar) displaying similar activity as the reference drug (IC50 = 13.12micromolar) and one of them even more potent with IC50 = 0.425micromolar.