Aims. T-2 toxin has destructive effect on different part of immune system such as Bone marrow, Spleen, Thymus, Lymphnode, and immune cells. The current study was designed to evaluate the effect of T-2 toxin on cell viability and Nitric Oxide (NO) release by mice peritoneal macrophages(mΦ).

 Methods. Mice were anesthetized and had their macrophages collected. The macrophages were washed three times, counted and plated out at 1x10⁵cells/well in 24 wells plate. Cells were incubated at 37⁰C and 5% Co₂ for 24h in the presence or absence of different concentrations of T-2 toxin. After that, supernatant was collected for NO assay (NO₂ was measured as an indicator of NO) and cell viability was checked by trepan blue die.

 Results. The Results showed that, maximum cell death and minimum NO release was induced in response to 100 ng/ml of T-2 toxin (P<0.01). There was no significant differences between control groups and those cells which received less than 1µg/ml T-2 toxin in term of cell death. In conclusion, it seems that cell death is Nitric Oxide independent, and T-2 toxin at low concentrations may have immunomodulatory effect on macrophage function.