Bladder cancer (BC) is the second most common malignancy of the genitourinary tract and the second leading cause of cancer death in patients with urinary tract malignancies. DNA methylation and histone modifications are important epigenetic mechanisms of gene regulation and play essential roles both independently and cooperatively in tumor initiation and progression. Aberrant epigenetic events such as DNA hypermethylation and altered histone acetylation have both been observed in bladder cancer, in which they affect a large number of genes. Although the list of aberrantly epigenetically regulated genes continues to grow, combination analysis including several candidate genes has given promising results of potential tumor biomarkers for the early diagnosis and risk assessment of bladder cancer. Thus, large-scale screening of aberrant epigenetic events such as DNA hypermethylation is needed to identify bladder cancer-specific epigenetic fingerprints. The reversibility of epigenetic aberrations has made them attractive targets for cancer treatment with modulators that demethylate DNA and inhibit histone deacetylases, leading to the reactivation of silenced genes. In this review, we examine the current literature on epigenetic changes in bladder cancer and discuss the clinical potential of cancer epigenetics for the diagnosis and treatment of this disease.