Bacterial blight of cotton is caused by Xanthomonas campestris pv malvacearum (Xcm), and affects all plant parts resulting in defoliation and thus yield loss. Infected leaves was collected from several regions in the Cotton Belt including North Carolina, Louisiana, Missouri, New Mexico and several locations in Texas. The pathogen was isolated from the diseased tissue and Xcm race identified based on disease reactions of a set of ten host differentials. The most virulent race 18 was the predominate race isolated from diseased tissue from all states. However, race 2 was isolated from disease tissue of cotton plants grown in Weslaco from seed that originated from Uzbekistan. The use of resistant cultivars is the most effective method for controlling bacterial blight in cotton.