Introduction: Mycotoxins in dairy cows can cause many non-specific symptoms often resulting from immune systemoverreaction. The study assessed the concentration of selected cytokines and acute phase proteins (APP) in cows with naturalmycotoxicosis before and after using a mycotoxin neutraliser. The cytokines were tumour necrosis factor alpha (TNF-α),interleukin 6 (IL-6) and interleukin 10 (IL-10), and the APP were serum amyloid A (SAA) and haptoglobin (Hp). Material andMethods: The research was carried out on an experimental group (Exp) of 10 herdmate Holstein-Friesian cows withmycotoxicosis. The control group (Con) was 10 healthy cows of the same breed from a different herd. Cows in the Exp groupwere administered the mycotoxin deactivator Mycofix for three months. Blood was drawn from Exp cows once beforeadministering Mycofix and a second time after three months of its use. Blood was also drawn from Con cows at the same times.Serum levels of TNF-α, IL-6, IL-10, SAA and Hp were assessed using ELISA. Results: The concentrations of all cytokines andHp in Exp cows were higher before treatment (P < 0.001) than those in Con cows. After three months of administering Mycofix,the concentrations of TNF-α and IL-6 were significantly lower than their pre-treatment levels (P < 0.001). The concentrations ofIL-6, IL-10, and Hp were still significantly higher than those in the Con group (P < 0.001). In cows with mycotoxicosis,simultaneous stimulation of antagonistic processes was noted: a pro-inflammatory process in the upregulation of TNF-α and IL-6, andan anti-inflammatory one in the upregulation of IL-10. Conclusion: Despite the absorbent’s use and the resolution of clinicalsymptoms in Exp cows, high levels of IL-10 and Hp and IL-6 were maintained. Assessment of the level of cytokines and APPappears to be a useful and precise tool for the evaluation and application of the appropriate dose of the mycotoxin absorbentor the evaluation of its effectiveness.