Thirty-three plants commonly used in West tropical Africa by traditional healers for the treatment of malaria were collected and ethanolic extracts were obtained by decoction. The antiplasmodial activity of extracts was evaluated in vitro against the chloroquine-resistant FcB1 strain of Plasmodium falciparum. Cytotoxicity was determined on the human MRC-5 and the rat L-6 cell lines. Of the 33 plant extracts, eight (24.5%) showed significant antimalarial activity (IC(50) values ranging from 2.3 to 13.7 microg/ml), 14 (42.5%) weak activity (IC(50) values ranging from 15 to 50 microg/ml) and 11 (33%) appeared inactive (IC(50) values >50 microg/ml). Five plants were of particular interest, associating good antiplasmodial activity and weak cytotoxicity. These five included Nauclea latifolia with known antiplasmodial activity and four, Fagara macrophylla, Funtumia elastica, Phyllanthus muellerianus and Rauvolfia vomitoria, for which the description of antiplasmodial activity is entirely novel.