The malaria, deadly parasite infection in its severe form, is widely spread in tropical zone where it rages in an endemic way. The emergence and the extension of Plasmodium resistance contributed to increase the morbidity and the mortality of this pathology in children under 5 years old. Facing the extend of this phenomenon, a monitoring of the expansion of the chemosensitivity proves to be necessary. The goal of the present study was to assess the sulfadoxine-pyrimethamine (S-P) efficacy according to the in vivo test WHO protocol of 14 days-follow-up. Children are treated to the S-P at the rate of 1/2 tablet per 10 kg of body weight in unique dose, then controls are done days 3, 7 and 14. At the end of this work, 179 on 475 subjects were effectively carriers of asexual parasites. So, the general plasmodic index and Plasmodium falciparum rate infection were respectively 37.7% and 100%. Among the 89 children followed until J14, those aged of 13 to 24 months represented 38% of the population of children suffering from Plasmodium malaria, against 7% of those aged between 49 and 59 months. In terms of therapeutic efficacy, 76.4% of adequate clinical and parasitological response (ACR) have been reached against 23.6% of therapeutic failure (TF).