Method of producing a radiometric physical phantom of a biological organism in order to experimentally determine under predetermined conditions of irradiation a volume distribution of the doses of radiation received by the phantom, representative of the distribution of doses that would be received by the biological organism placed in the same conditions of irradiation, the biological organism having at least two volumes of biological tissues of which the chemical compositions and the densities are markedly different, the method of producing comprising the steps consisting in: from one or several anatomical three-dimensional images of the tissues in terms of chemical compositions and densities, determining a radiological three-dimensional model, representative of the absorption and of the diffusion of the radiation inside the biological organism, by grouping together into radiological organs the mutually adjacent tissues and having chemical compositions and densities which are similar, each radiological organ geometrically occupying in space a radiological volume, equal or approaching via smoothing the contours of its envelope the sum of the volumes of all of the tissues grouped into the same radiological organ, and being characterised by a radiological class identifying the range of the chemical compositions and densities which are similar to the tissues grouped into the same radiological organ; then from the radiological model, carrying out using 3D printing, a material framework of the physical phantom by reproducing each radiological volume by an enclosure filled with air and delimited by a wall, the wall consisting of a 3D printing ink; then filling each enclosure of the material framework of the phantom, associated with a radiological organ, by a dosimetric gel of which the physical characteristics are close or identical to those of the class of the chemical compositions and densities of the radiological organ. from one or several anatomical three-dimensional images of the tissues in terms of chemical compositions and densities, determining a radiological three-dimensional model, representative of the absorption and of the diffusion of the radiation inside the biological organism, by grouping together into radiological organs the mutually adjacent tissues and having chemical compositions and densities which are similar, each radiological organ geometrically occupying in space a radiological volume, equal or approaching via smoothing the contours of its envelope the sum of the volumes of all of the tissues grouped into the same radiological organ, and being characterised by a radiological class identifying the range of the chemical compositions and densities which are similar to the tissues grouped into the same radiological organ; then from the radiological model, carrying out using 3D printing, a material framework of the physical phantom by reproducing each radiological volume by an enclosure filled with air and delimited by a wall, the wall consisting of a 3D printing ink; then filling each enclosure of the material framework of the phantom, associated with a radiological organ, by a dosimetric gel of which the physical characteristics are close or identical to those of the class of the chemical compositions and densities of the radiological organ.