Halofantrine has been given to 14 children and 15 adults suffering from an acute attack of P. falciparum malaria and living in Dakar (Senegal) to a total dose of 24 mg/kg/body weight for the first group and 1,500 mg for the second in 3 times at 6-hourly intervals. This treatment has allowed the fever to clear in all cases within 36.3 +/- 19.9 hours and headache to disappear at D3 in 93.1% of cases. A reduction by 93.6% of the average parasite density which amounted before treatment to 27,710 trophozoites/mm3 of blood has been recorded from the day following the beginning of treatment and the parasite clearance obtained in all the patients of whom had chloroquine-resistant P. falciparum strains in mean time of 58.0 +/- 14.7 hours. In 3 cases (10.7%) a recrudescence of parasitemia has been noticed in D14. Only 1 of them was treated again with halofantrine which proved efficient from D2. The only adverse reactions have been nausea, vomiting, a slight diarrhoea and dizziness which affected only 13.8% of the patients. No abnormality has been noticed at a biological level. These results confirm the efficacy and good tolerance of halofantrine and allow to list it among the resource drugs used for the treatment of chloroquine-resistant P. falciparum malaria in our area.