Fusarium oxysporum is a ubiquitous, widespread, soil-borne fungus with significant economic importance. More than 120 plant species, including some economically important crops like tomato, are susceptible to infection with this fungus. A series of laboratory experiments were conducted to assess the inhibitory effect of eight fungicides on F. oxysporum. These fungicides can be classified into a single mode of action fungicides (Flint, Previcur N, Punch and Topas) or multi-mode of action fungicides (Acrobat copper, Consento, Maxim XL and Roxyl Plus). Results revealed that, the single mode of action fungicides such as Punch (Flusilazole) and Topaz (Penconazole) were the most toxic to the F. oxysporum with IC50 = 0.152 and 0.989 ppm, respectively. While Maxim XL (Mefenoxam + Fludioxonil) was the most effective multi-mode of action fungicide with IC50 =1.66 ppm. The influence of the most effective fungicide on F. oxysporum on the fungal antagonist Trichoderma harzianum was investigated. All tested fungicides had a potent effect on T. harzianum