Metronidazole is the most widely used drug in trichomoniasis therapy. However, the emergence of metronidazole-resistant Trichomonas vaginalis isolates calls for the search for new drugs to counter the pathogenicity of these parasites. Classifiation models for predicting the antitrichomonas activity of molecules were built. These models were employed to screen antiprotozoal drugs, from which 20 were classifid as active. The in vitro experiments showed moderate to high activity for 19 of the molecules at 10 μg/ml, while 3 compounds yielded higher activity than the reference at 1 μg/ml. The 11 most active chemicals were evaluated in vivo using Naval Medical Research Institute (NMRI) mice. Benznidazole showed similar results as metronidazole, and can thus be considered as a potential candidate in antitrichomonas therapy.