Abstract: Background and Objective: Biological control refers to purposeful utilization of introduced or resident living organisms other than disease resistant host. Antioxidants protect cells against the damaging effects of reactive oxygen species otherwise called, free radicals such as singlet oxygen, super oxide, peroxyl radicals, hydroxyl radicals and peroxynite which results in oxidative stress leading to cellular damage. Cytological abnormalities in Vicia faba, studies are carried out in root tips as the using of this area in induction of chromosomal aberrations is one of the oldest, simplest, most reliable and inexpensive method. Therefore, this study aims to determine the cytotoxic and mutagenic effect using chromosome aberration assay (Vicia faba). Materials and Methods: Vicia faba (broad bean) seeds (2n = 12 chromosome) (Cultivar: Giza 716), were obtained from the Agriculture Research Center, Crop Research Section, Sakha, Kafr El-Sheikh, Egypt. The seeds were prepared into slides via serial steps of fixation and squashing. Data of different treated groups of root tips were represented as Mean±SE and statically analyzed using t-test to determine the significance of the differences between treatments and control at the 0.05 level of probability. Results: Results showed the highest percentage of MI% was 23.77% at 20 mM of citric acid for 24 h, while the lowest percentage was 9.54% at H2O+Trichoderma viride for 48 h. The highest percentage of abnormal mitosis was 43.53 and 37.24% at 24 h for 20 mM of (Aa+T. harzianum) and 3 mM of salicylic acid, respectively compared with control sample 9.37%, while the highest abnormal mitosis percentage at 48 h was 64.93 and 43.13% for (H2O+T. viride) and 20 mM citric acid. Conclusion: It was concluded that Trichoderma can be used safely as bio-control agents against pathogenic microbes. To use bioagents like antioxidants especially ascorbic acid and bio-control fungi especially T. harzianum in future in replacement of chemical fungicides (unsafe and inexpensiveness).