Fasting is considered as one of the most important religious and social practices of Islam, Numerous biological and behavioral changes occur in some people who observe the fast in Ramadan and some researchers believe that urinary stone increases during this month. Some believe that increased incidence of urinary stones in Ramadan is not related to fasting, but to the rise of weather temperature in hot months, and an increase in humidity. After reviewing some studies about the relationship of urinary stones and their incidence in Ramadan are not alike and are even sometimes contradictory. The aim of this study is to evaluate the effects of fasting on kidney and urinary stones.