The aim of this work was to evaluate lemon-scented gum (Corymbia citriodora) extracts in inhibiting the in vitro growth of Xanthomonas spp. The treatments consisted of aqueous, infusion, alcoholic and boiling extracts, in addition to the control with antibiotics. The methodology used to assess the antagonism was the double layer diffusion. The extracts were tested at 50, 35 and 15% concentration. None of the extracts inhibited the growth of X. citri pv. glycines, only the antibiotic bacitracin. As for X. vesicatoria, it was observed that only the alcoholic extract of C. citriodora leaves inhibited its growth, with emphasis on the 35% alcoholic extract, in addition to the antibiotics streptomycin and bacitracin. The growth of X. campestris was inhibited by alcoholic and aqueous extracts, highlighted on 50% and 35% alcoholic and 50% aqueous extracts, as well as by streptomycin and penicillin. The aqueous and alcoholic extracts of lemon-scented gum showed potential in the in vitro control of Xanthomonas and new studies will be carried out with new concentrations and in vivo control of diseases caused by these bacteria.