Thirty patients of uncomplicated Plasmodium falciparum malaria completed a clinical trial of arteether alpha/beta conducted in a malaria endemic tea garden of district Dibrugarh, Assam. Arteether was given intramuscularly in once a day dose of 150 mg for three consecutive days. The cure rate was 100 per cent with mean fever and parasite clearance time of 42.4 +/- 17.5 and 37.6 +/- 13.6 h respectively. Recrudescence/reinfection rate was 6.7 per cent. Palpable spleens of twenty out of twenty one cases on day 0 became non palpable within 28 days. Following the treatment, percentage of hemoglobin improved marginally with no remarkable change in total and differential leucocyte count. Arteether alpha/beta, besides being a potent and fast acting schizontocidal drug, also exhibited gametocytocidal action on P. falciparum.