© 2018 by Wroclaw Medical UniversityBackground. Piezo1/2, a mechanically activated ion channel, is believed to play an important role in bladder carcinogenesis process. Piezo1/2expression has not been previously reported in urinary bladder carcinoma, and little is known about its significance in bladder carcinogenesis. Objectives. In our study, we aimed to evaluate the Piezo1and Piezo2expression as developmental in mouse bladder tissue and bladder cancer tissue of mice and humans. Material and methods. The detection of developmental expression was performed on P0–P90 days in bladder tissue of Balb/c strain mice. Mice were divided into bladder cancer (n = 40) and control groups (n = 10). Bladder cancer in mice was created by using N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). In the study, 60 human subjects were included, whose normal tissues were used as controls. After the histopathological evaluation, the expression of Piezo1/2genes was examined by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry in tumor and normal tissues. Results. In developmental period of the mice, Piezo1expression increased on days 21 and 90, whereas Piezo2 expression increased on day 7 and decreased on day 90 in mouse bladder tissues. There was a significant increase in the expression of Piezo1/2in both cancer groups compared to the control group. Piezo1expression was significantly increased at tumor size, stage and grade. Piezo2expression was upregulated in high grade tumors in human subjects. Conclusions. The developmental changes of Piezo expression on specific days demonstrate the role of these channels in bladder cancer development. The dysfunction of Piezo1/2 expression may contribute to the carcinogenesis of bladder cancer by causing proliferative changes and angiogenesis. The expression of Piezo1/2can provide new prognostic information for disease progression.