Abstract <p>The influence of weak microwave and ultraviolet radiation on the structure formation of zirconium oxyhydroxide prepared at different nucleation and growth rate ratios is studied. Thermal behavior, heat-induced phase changes, and morphology of the synthesized samples are studied by thermogravimetry, differential scanning calorimetry and mass spectrometry of gaseous thermolysis products, as well as by powder XRD and high-resolution transmission electron microscopy. It is established that such radiation promotes the decrease of the temperature of amorphous zirconium dioxide crystallization, formation of well-crystallized zirconium dioxide nanoparticles and can be therefore be used in the directed synthesis of nanocrystalline materials based on such compounds. The irradiation effect is most pronounced in the case of long-term hydrolysis of aqueous zirconium oxychloride.</p>