A total of 13 Rhizobium strains were isolated from the root nodules of cluster bean [Cyamopsis tetragonoloba (L.) Taub.] plant which was collected from 10 different villages of three districts (Bhiwani, Hisar, and Mahendergarh) of Haryana state. On the basis of morphological analysis, they were recognized as rhizobia. | Siderophore production by rhizobia isolated from cluster bean [Cyamopsis tetragonoloba (L.) Taub.] growing in Semi-arid regions of Haryana, India