T-2 toxin is a secondary fungal metabolite produced by various species of fusarium. In this study, the in vitro cytotoxicity of T-2 toxin in the human hepatoma cell line (HepG2) was determined using three methods, including neutral red dye adsorption, trypan blue dye exclusion, and uptake of radiolabeled 3 H-thymidine. The 50% lethal concentration of T-2 toxin was found to be similar for all three, accounting for 2.39, 2.96, and 3.44 ng/mL, respectively, as determined by these assays. Significant correlations were also observed among the three methods (p <. 05 through p <. 005). These results suggest that all three methods are reliable and are comparable for determining the 50% lethal concentration of T-2 toxin. It is concluded that the neutral red cytotoxicity assay may be preferable to other methods because of its simplicity, its use of nonradioactive materials, and its objectivity.