Among strategies to combat malaria, the search for new antimalarial drugs appears to be a priority. Sheering for new antimalarial activities, four plants of the traditional medicine of Burkina Faso: Combretum micranthum, Khaya senegalensis, Pterocarpus erinaceus and Sida acuta, were tested in vitro on fresh clinical isolates of Plasmodium falciparum. The screening showed that Sida acuta has a significant activity (IC 50< 5 μg/ml), and Pterocarpus erinaceus has a moderate activity (5 μg/ml< IC 50< 50 μg/ml). Further chemical screening showed that the activity of the most active plant, Sida acuta, was related to its alkaloid contents.