The present invention discloses a method of evaluating the immunotoxicity of a hydrophobic test substance, comprising (1) culturing immunocompetent cells in a culture system containing a hydrophobic test substance and a surfactant, (2) obtaining a survival rate of the immunocompetent cells after the culturing (1), and (3) evaluating the immunotoxicity of the hydrophobic test substance from the survival rate obtained in (2).