BACKGROUND Testis-specific gene antigen 10 (TSGA10) is a tumor suppressor in several types of human malignancy. However, there have been few studies that have investigated the role of TSGA10 in bladder cancer. This study aimed to investigate the expression of TSGA10 in human bladder cancer cell lines and bladder cancer tissues and its effects on patient prognosis. MATERIAL AND METHODS The expression of TSGA10 in 40 tissue samples of bladder cancer and matched normal adjacent bladder tissue, and five human bladder cancer cell lines was assessed by immunohistochemistry, Western blot, quantitative reverse transcription polymerase chain reaction (qRT-PCR), and flow cytometry. The correlation between the expression level of TSGA10 and the clinicopathological features of patients with bladder cancer was analyzed and overall survival (OS) in patients with bladder cancer was determined by Kaplan-Meier curves. RESULTS Upregulation of TSGA10 expression in tissues from patients with bladder cancer was compared with normal adjacent bladder tissue and was significantly correlated with gender, metastasis, lymphovascular invasion, and tumor stage in bladder cancer. In bladder cancer cell lines, down-regulation of TSGA10 reduced cell apoptosis and increased cell migration, and resulted in the formation of an epithelial-mesenchymal transition (EMT) phenotype. Overexpression of TSGA10 resulted in an increased apoptosis rate of tumor cells, reduced cell migration, and contributed to the reversal of the EMT phenotype. CONCLUSIONS These findings support that TSGA10 deserves further study as a potential novel prognostic biomarker in bladder cancer.