This study was conducted to prepare and characterize activated carbon (AC) and to evaluate its protective effect against deoxynivalenol (DON) toxicity in rats compared to Egyptian montmorillonite (EM). AC was prepared using a single-step chemical activation with phosphoric acid (H₃PO₄). The resulted AC has a high surface area and a high total pore volume. Male Sprague–Dawley rats were divided into 6 groups (n = 10) and treated for 3 weeks as follow: the control group, the groups fed AC or EM-supplemented diet (0.5% w/w), the group treated orally with DON (5 mg/kg b.w.) and the groups fed AC or EM-supplemented diet and treated with DON. Blood and liver samples were collected for different analyses. Treatment with DON increased liver function enzymes, lipid peroxidation, tumor necrosis factor α, DNA fragmentation, decreased hepatic glutathione content, up regulating mRNA Fas and TNF-α genes expression and increased micronucleated polychromatic erythrocytes and normochromatic erythrocytes in bone marrow. Co-treatment of DON plus AC or EM succeeded to normalize the levels of the biochemical parameters, reduced the cytotoxicity of bone marrow and ameliorated the hepatic genotoxicity. Moreover, AC was more effective than EM and has a high affinity to adsorb DON and to reduce its cytotoxicity and genotoxicity.