[en] Complete text of publication follows. Different radiochromic dosimeters in various forms have been introduced over the past two decades for routine dosimetry purposes in radiation processing. The basis of this application is that certain water soluble tetrazolium salts become permanently radiochromic by radiolytic reduction in deoxygenated buffered solutions. For a few compounds these characteristics have been studied for potential dosimetry application, thus 2,3,5-triphenyl-tetrazolium chloride and 2-nitrophenyl-3,5-diphenyltetrazolium chloride have already been suggested for higher and lower dose determination respectively. The reactions of another tetrazolium compound, the dichloride salt of nitro blue tetrazolium (NBT), a well-known quantitative reagent in complex chemistry, has not yet been studied from the point of view of dosimetric application. Thus the aim of the present work was the study of its characteristics for dosimetry purposes. In our investigations different concentrations of NBT have been studied in aqueous and aqueous-alcoholic solutions in the dose range of 0.1-50 kGy by measuring mainly the absorbance of the monoformazan radiolysis product. Detailed investigations were carried out to study the effect of a/ NBT concentration, b/ pH in the range of 5-11 and c/ oxidative and reductive conditions on the colour change of the solutions including the role of the water insoluble diformazane as final radiolysis product. On the basis of these investigations the potential use of NBT for dosimetry purposes will be discussed in the paper