Purpose This study is aimed to the investigation of the features of morphological changes in the urinary bladder of mature rats. Results Received results shown that the experimental group of rats that had the intake of heavy metal salts (HMS) mixture during 30 and 90 days were observed histological and immunohistochemical changes in all structures of the urinary bladder. Depending on the period of influence of heavy metal ions on the wall of the organ, the pathological changes developed in cellular layers of the wall can lead to degenerative and later to atrophic and sclerotic changes. Conclusions This study demonstrates that high concentrations of HMS can significantly influence the body. The histological and immunohistochemical studies showed that the influence of the HMS combination leads to deep morphological changes in all structures of the urinary bladder. These changes depend on the period of intake of HMS. Analysis of the obtained results demonstrates the dependence of expression of morphological changes in the urinary bladder on the experiment duration. The final result of these changes may lead to the disorders of bladder’s functions.