Maize constitutes more than 75% of the food base of the Inter-Andean Valleys and is one of the foods most at risk of fumonisin and yet there is no information about the incidence level of fumonisins in this region. In this project we collected 174 samples from organic maize producers communities of the inter-Andean valleys that work with the Valles Foundation, the number of fumonisins was determined by the Elisa Method, with 0.05 ng/ml being the lowest value obtained in the community of Alcalá and 12.05 ng/ml,Highest value obtained in the community of Mizque.