The present paper deals with study of the resistance against five antibiotics in a phytopathogenic bacterium Xanthomonas campestris (Pammel) Dowson. When the antibiotics were added to the solid medium in which the bacteria were grown, the colonies resistant to the streptomycin and erythromycin appeared even in the highest concentration used; as to the penicillin, aureomycin and cloranfenicol when in concentrations higher than 200 mcg/ml, 0,3 mcg/ml and 128 mcg/ml respectively, resistant colonies did not appear. So, the results show that the penicillin was the least efficient antibiotic and aureomycin the most effetive to Xanthomonas campestris.