The incidence of renal cell carcinoma (RCC) is high in Western and Northern Europe and North America, andlow in Asia. Although the incidence of RCC in Japan is lower than the rates in the other industrialized countries,there is no doubt that it is increasing. In this paper, we would like to introduce the summary of findings of JACCstudy, which evaluate the risk factors for RCC in a Japanese population. JACC study suggests nine risk factors(i.e., smoking, obesity, low physical activity, hypertension, diabetes mellitus, kidney diseases, beef, fondness forfatty food and black tea) and one preventive factor (i.e., starchy roots such as taro, sweet potato and potato) ina Japanese population. In Japan, however, drinking black tea may be a surrogate for westernized dietary habitswhile eating starchy roots may be a surrogate for traditional Japanese dietary habits. Further studies may beneeded to evaluate risk factors for RCC because the number of cases is small in our studies.