A rapid test for amanitins is proposed on the basis of their complexation with ethydium bromide leading to an intensively fluorescent adduct; the fluorescence band of the product has a shorter wavelength than that of ethydium bromide, which ensures the high specificity of the analysis. The fluorescence intensity in the system of ethydium bromide - amanitin grows linearly with the concentration of amanitin in the range 0.2-1.7 mu M at the constant concentration of ethydium bromide, 0.6 mu M. The detection limit is 1 mu M, the time of the development of the analytical signal is up to 5 s.