Biological control of Fusarium udum causing wilt disease of pigeonpea was studied in vitro, as well as, in vivo. Aspergillus flavus, Aspergillus niger, Bacillus licheniformis (strain-2042), Gliocladium virens, Penicillium citrinum, and Trichoderma harzianum, which were found to be the most potent ones in inhibiting the radial colony growth of the test pathogen, were used as biological control by amending their inocula at different concentrations in pots and in pathogen-infested soil in the fields. Maximum reduction of the wilt disease was observed with G. virens both in pots and in the fields. The population of F. udum was found to be markedly reduced when the antagonists were applied in the soil. The study establishes that G. virens can be exploited for the biological control of wilt disease at field level.