Objective: To characterize the weed flora in the corn-growing plots and assess their harmfulness in the Haut-Sassandra region in the center-west of the Ivory Coast.Methodology and results: The weed flora of the maize crop in the Haut-Sassandra region was evaluated using the method called « field tour ».Results: The work made it possible to identify 105 species of weeds belonging to 80 genera distributed in 27 families.The dominant families are: The Poaceae (37,81%), the Asteraceae (10,48%), the Euphorbiaceae (8,57%), the Fabaceae (8,57%) and the Rubiaceae (6,67%). Dicotyledons are in the majority with 67% of species.Agronomically speaking, Croton hirtus, Porophyllump ruderale, Mitracarpus villosus, Digitaria gayana and Brachiara villosa are the most harmful weeds in the area.Conclusion and appliation of the results: This study mmade it possible to characterize the weed flora of maize. The data obtained are necessary for the development of effective control means.