Severe acute malnutrition is a real public health problem in the Vaku health zone, we note the persistence of cases and the increase in infant and child mortality. This study aims to determine the prevalence and determinants of severe acute malnutrition. This is a cross-sectional analytical study of 479 children under 5 years of age with acute malnutrition, received in the structures of this health zone in 2020. Selected according to the Z-score weight/height or mid-upper arm circumference. The prevalence of severe acute malnutrition was 3.8%, the Khele health area (6.6%) was in first position. Male sex was more concerned and age between 12 and 24 months had the highest prevalence (4.7%). We performed multivariate analysis with logistic regression of associated factors. Non-exclusive breastfeeding, inadequate complementary feeding, monthly income ≤ US$ 30 of heads of household and non-attendance at SPC have been identified as potential determinants of severe acute malnutrition in this health zone. Incomplete immunization status, household size of more than six people and access to difficult food were identified as protective factors for severe acute malnutrition. The other factors studied did not present the link with malnutrition in this health zone. Several cited studies found similar results. We suggest the effective integration of infant and young child feeding activities into the structures of this health zone that could reduce this prevalence.