This thesis was focused on the search for antiparasitic compounds from tropical plants. Eleven plants from Brazil, thirty-eight from Niger and one from Cameroun were selected based on their traditional use and collected. Each plant extract was evaluated for its antiparasitic activity against Trypanosoma cruzi, Trypanosoma brucei rhodesiense, Leishmania donovani and Plasmodium falciparum at the Swiss Tropical Public Health Institute in Basel. In addition, the cytotoxicity was evaluated. The selection of plant extracts was based on the antiparasitic activity, molecular networks built using LC-HRMS/MS and literature search. For some of the selected plant extracts, bioassay-guided fractionation was carried out to isolate the compounds. A total of 41 compounds of various structures was isolated and 13 of them are described here for the first time. All of the isolated compounds were tested for their antiparasitic activities.