Seven sulfadoxine-pyrimethamine resistant Plasmodium falciparum infected patients and 2 patients with mixed (P. falciparum and P. vivax) infection were given Artemether. The results showed that Artemether is effective in sulfadoxine-pyrimethamine resistant malaria. The mean fever clearance time and parasite clearance time of patients treated with Artemether is shorter than those treated with chloroquine, quinine or sulfadoxine/pyrimethamine. In one patient with mixed infection all parasites disappeared but P. vivax reappeared on day 11 and on day 14 after two consecutive courses. In another P. vivax reappeared on day 21.