Calcium oxalate nephrolithiasis is a relatively common disease. The prevalence in the general population may range from 10 to 12 percent, and 0.4 to 1 percent of new cases are reported every year according to different series. Without specific pharmacological therapy, the recurrence rate in patient with established diagnosis of nephrolithiasis is extremely high and may range from 15 to 20 percent per year, with a cumulative incidence at five years ranging from 27 to 50 percent.Although genetic factors play an important role in the development of nephrolithiasis, environmental factors such as diet also appear to affect stone formation. Potassium citrate is also effective in preventing stone recurrence in patients with calcium oxalate nephrolithiasis. Low tolerability, however, may remarkably limit the use of these medication. Citrus fruits are a natural rich source of citrate and diet supplementation with juice of citrus fruits may represent a valuable alternative option to supply citrate without exposing the patients to the adverse effects of citrate containing medications. Among the most commonly consumed citrus fruits, lemons contain the greatest concentrations of citric acid (49,2 g/Kg);a half cup of pure lemon juice can provide a daily amount of citrate comparable to that of a standard daily dose of alkali citrate medications.