Indianbean (Lablab purpureus L.) is an important pulse crop of Gujarat. Occurrence of leaf spot (Phoma tropica) was observed seriously in south Gujarat in rabi 2006. Due to hazardous effects of chemicals, plant pathologists have diverted to search the alternative methods to control plant diseases which may cause little or no adverse effect on environment. Recently disease control through the use of antagonists in the laboratory and field has been achieved successfully. In the present study, attempts have been made to identify antagonistic microorganisms against Phoma tropica in vitro. Interaction studies on the effect of known antagonists were carried out by three methods viz., dual culture, pathogen at the periphery and pathogen at the centre which revealed that strong antagonistic effect of T. harzianum followed by A. niger, and T. viride against P. tropica .