Mycotoxins, such as aflatoxin B 1 (AFB 1), pose a serious threat as biological weapons due to their high toxicity, environmental stability, easy accessibility and lack of effective therapeutics. This study investigated if blood purification therapy with CytoSorb (CS) porous polymer beads could improve survival after a lethal aflatoxin dose (LD 90). The effective treatment window and potential therapeutic mechanisms were also investigated. Sprague Dawley rats received a lethal dose of AFB 1 (0.5-1.0 mg/ kg) intravenously and hemoperfusion with a cS or control device was initiated immediately, or after 30, 90, or 240-minute delays and conducted for 4 hours. The CS device removes AFB 1 from circulation and significantly improves survival when initiated within 90 minutes of toxin administration. Treated subjects exhibited improved liver morphology and health scores. changes in the levels of cytokines, leukocytes and platelets indicate a moderately-severe inflammatory response to acute toxin exposure. Quantitative proteomic analysis showed significant changes in the level of a broad spectrum of plasma proteins including serine protease/endopeptidase inhibitors, coagulation factors, complement proteins, carbonic anhydrases, and redox enzymes that ostensibly contribute to the therapeutic effect. Together, these results suggest that hemoadsorption with cS could be a viable countermeasure against acute mycotoxin exposure. Aflatoxins are toxic secondary fungal metabolites (mycotoxins) produced by fungus from the genus Aspergillus that cause severe acute reactions that can be lethal. Aspergillus species are important human pathogens and the toxic metabolites appear to act as virulence factors to suppress the immune system in invasive aspergillosis 1. Aflatoxins cause damage to the liver resulting in hemorrhagic liver necrosis, steatosis, bile duct proliferation and subsequent organ failure and have been detected in pulmonary lesions of immune-compromised patients with systemic aspergillosis 2. Aflatoxin B 1 (AFB 1), the most potent toxin of the 14 naturally occurring aflatoxin variants, is extremely cytotoxic, genotoxic, and carcinogenic 3,4. In the liver, cytochrome P450-modified AFB 1 forms DNA adducts that lead to impaired cellular function, carcinogenesis and/or cell death and organ failure 5,6. Acute aflatoxin poisoning from mold contaminated foods has been linked with numerous deaths in several instances 7,8. Importantly, mycotoxins pose a serious threat as potential biowarfare agents due to their inherent stability and ease of manufacture. The toxins can be readily weaponized into aerosol form and dispersed over a wide area to elicit mass casualties through both inhalation and dermal exposure 9. There have been several reported incidents of use of mycotoxins as bioweapons in Southeast Asia and the Gulf States 10,11. Early symptoms of mycotoxin exposure in bio-warfare manifest rapidly in minutes to hours and can include burning, pain, wheezing, nausea, vomiting, tearing, weakness, bleeding and a host of other symptoms...