Background. The overall effect of fruit and vegetable intake on urinary stone risk profile is not yet known. Methods. We studied the effect of a two-week period of fruit and vegetable elimination on urinary stone risk profile in 12 normal adults, and of supplementing the diet with a fair quantity of low-oxalate fruits and vegetables in 26 idiopathic calcium stone formers characterized by hypocitraturia and a very low fruit and vegetable intake in their usual diet. Results. In the normal subjects, the elimination of fruits and vegetables from the diet decreased the urinary excretion of potassium (−62%), magnesium (−26%), citrate (−44%) and oxalate (−31%), and increased that of calcium (+49%) and ammonium (+12%) (P