The present research deals with the study of antagonistic effect of microorganism against black root rot disease caused by Fusarium oxysporum and collar rot disease caused by Rhioctonia solani. The antagonistic soil bacteria, Bacillus species Pseudomonas fluorescens were isolated from tomato field soil by serial dilution method. The tomato pathogens were isolated from the infected plants which were collected from tomato field. The antagonistic microorganisms against the fungal pathogens were observed by Dual Culture Technique and antibiotic interaction. The growth of the pathogen in the treated plate and control plate were measured and the efficiency of antagonistic organisms control the pathogens were expressed as % inhibition of mycelia. Among two organisms, Bacillus spp (36.7%) was found to have more antagonistic activity against test pathogens. The Pseudomonas spp showed 35.5% of growth inhibition against test pathogens. In this study, both the antagonistic bacteria effectively control the Fusarium oxysporum than Rhizoctonia solani.