The present invention provides a nematicide composition and a method using said composition, for controlling plant pathogenic nematodes. Said composition comprises as active principles, oligomers derived from monomers of gallic acid, quinic acid, caffeic acid and methylated derivatives thereof; also contains hydrocolloids, carbohydrates, water-soluble proteins and agriculturally acceptable excipients. The method for controlling nematodes comprises applying the nematicide composition on the soil of infected crops at appropriate doses and time intervals.COMPOSICIÓN NEMATICIDA QUE COMPRENDE OLIGOMEROS DE ÁCIDO GÁLICO Y ÁCIDO QUINICO, GALACTOMANANOS E HIDROCOLOIDES ADICIONALES Y MÉTODO PARA EL CONTROL DE NEMATODOS.