Amphibians are widely known as a prolific source of bioactive metabolites. In this work we isolated and characterized compounds with antiparasitic activity from the oocytes of the toad Rhinella alata collected in Panama. Bio-guided isolation and structural elucidation was carried out using chromatographic and spectroscopic techniques. The organic crude extract was subjected to solid phase extraction followed by HPLC purification of the fraction with in vitro activity against Trypanosoma cruzi trypomastigotes. Seven steroids (1-7) of the bufadienolide family were isolated and their structures determined using NMR and MS analyses; of these 19-formyl-dyscinobufotalin (3) is reported as a new natural product. Compounds 1, 3-7, resulted with a good anti-trypanosomal activity profile, among these 16β-hydroxyl-hellebrigenin (1) and bufalin (7) showed significant selectivity for T. cruzi. Furthermore, molecular docking analysis showed compounds 1, 3 and 7 interact through H-bonds with the amino acid residues GLN-19, ASP-158, HIS-159 and TRP-177 from cruzipain, at the catalytic site. Given the lack of therapeutic options to currently treat the American trypanosomiasis, this work can serve as the basis for further studies that aim the development of bufadienolides or their derivatives as drugs against Chagas disease.