Spindle and kinetochore-associated protein 1 (SKA1), a component of microtubule-binding complex of kinetochore, is essential for proper chromosome segregation. Recently, SKA1 has been shown to be involved in malignant progression of several human cancers. However, its role in bladder cancer is still unknown. To evaluate the function of SKA1 in bladder cancer cells, the authors employed an RNA interference lentivirus system to deplete its expression in both BT5637 and T-24 bladder cancer cells. The cell proliferation was significantly decreased in both cell lines after SKA1 knockdown. Moreover, the colony formation capacity was impaired by SKA1 silencing. Flow cytometry analysis showed that depletion of SKA1 led to cell cycle arrest at S phase. Furthermore, knockdown of SKA1 in T-24 cells obviously downregulated the expressions of CDK4 and Cyclin D1, and alleviated the activations of ERK2 and AKT, conducive to cell growth inhibition. These findings suggested that knockdown of SKA1 could potently suppress bladder cancer cell proliferation in vitro and lentivirus-mediated silencing of SKA1 might serve as a novel strategy for gene therapy of bladder cancer.