We investigated thee ffects of neem extract and azadirachtin on phytopathogens and plant growth-promoting microorganisms, and attempted to identify whether they exhibit antimicrobial activity. Azadirachtin and neem extract were tested for antimicrobial activity usingagar well diffusion method. The phytopathogens tested in this study were X. campestris pv. campestris, P. carotovorum, and F. oxysporum, which cause black rot in crucifers, soft rot, and Fusarium wilt disease in vegetables, respectively (Agrios, 2005).