Background: The pharmacotherapy of cutaneous leishmaniasis is invasive and presents several adverse reactions, which reinforces the need for topical and less toxic alternatives. Methods: Topical microemulsions containing phenolic compounds from Libidibia ferrea (Fabaceae) were developed, physicochemically characterized, and tested in hamsters (Mesocricetus auratus) experimentally infected with Leishmania amazonensis. After treatment, clinical progression of lesions, histopathological alterations, and parasite load were evaluated. The dichloromethane (DCM) fraction of the extract was analyzed by mass spectrometry, and the main compounds were isolated. Results: The optimized microemulsion effectively controlled lesion progression, showing only a 25% increase in lesion volume, compared to a 383% increase for the group without treatment, and presented a moderate inflammatory response. A new phenolic compound, named libidine (phenylpropanoic acid derivative), along with methyl gallate, was isolated from the DCM fraction. Conclusions: The topical formulation was as effective as Glucantime(R) (antimonial standard treatment) and produced a significant reduction in parasite load, consistent with the antileishmanial activity previously reported for phenolic acids and their derivatives.  Kulcsszavak: Leishmania amazonensis, Libidibia ferrea, organic acid derivatives, microemulsion system, topical treatment