Study objective was to hypothesized that the consumption of green leafy vegetables (GLV), including cruciferous vegetables (CV), significantly reduces the incidence of urothelial cancers. The hypothesis was answered by using the experimental approach of meta-analysis by synthesizing relevant worldwide studies that address the association between the consumption of GLV and risk of incidence of the disease. Three models were used, and the first indicated an overall odds ratio effect size of the ‘almost every day’ highest vs. lowest quantile intake category of GLV on urothelial cancer as: OR = 0.749 (95% CI .678 to .827), p<.001. The second model indicated an overall hazard ratio effect size as: HR = 0.803 (95% CI .699 to .922), p=.002. The third model indicated an overall risk ratio effect size as: RR = 0.896 (95% CI .691 to 1.16), p=.405.