Fusarium wilt of tomato caused by Fusarium oxysporum f.sp. Lycopersici is considered one of the most important diseases, which annually occurred in tomato plants (Lycopersicon esculentum) and causes great losses in tomato production. So the present study aimed to find the best strategy to control or at least reduce disease severity. This strategy include: studying some factors which may affect on the disease severity like virulence of FOL isolates as well as reaction of different tomato hybrids and also investigate the best means for controlling the disease like using some microorganisms in order to antagonize the pathogen and protect tomato from infection either through direct effect of these bio agent on the pathogen or through their ability to induce systemic or local resistance in plants