Bladder cancer originates in the epithelial lining of the bladder's mucosa and develops in association with several habitual, industrial, and environmental risk factors via papillary and non-papillary pathways. In this chapter we review novel concepts concerning the molecular mechanisms of early field change in bladder neoplasia stemming from whole-organ genomic mapping studies. These mechanisms are discussed in the context of molecular pathogenesis of bladder cancer and in relation to treatment and biomarker-based detection strategies.