KRAS is a gene that encodes one of the several proteins in the growth factor signaling pathway(s) and is important in the development and progression of a variety of cancers. KRAS can harbor oncogenic mutations that yield a constitutively active protein. The frequency of the KRAS gene mutations in urothelial carcinoma of urinary bladder is very low (3% to 7%), and these mutations occur in all stages and grades. In the context of bladder tumors, mutations in the KRAS gene do not appear to be predictors for recurrence-free, progression-free and disease-specific survival according to some studies.