UNC5 receptors are putative tumor suppressors whose expressions are lost in some cancers, but the role of UNC5A during DNA damage in bladder cancer remains undefined. To investigate into the potential function of UNC5A in bladder cancer, we examined UNC5A expression with real-time RT-PCR and Western blotting in bladder cancer specimens and analyzed the effects of chemotherapeutic drug on the expression level of UNC5A and knocking down of UNC5A on chemotherapeutic drug-mediated cell death. In this current study, we found low expression of UNC5A in bladder cancer, an effective induction of UNC5A by cisplatin in bladder cancer cell lines with wt p53, and a significant reduction of cisplatin-mediated cell death following silencing the endogenous UNC5A. Moreover, colony formation assay indicated that reexpression of UNC5A inhibited the survival of 5637 cells. Together, these data suggest an important role for UNC5A, a candidate tumor suppressor, in predicting response to DNA damage induced by chemotherapeutic drug and regulating cell death in bladder cancer.