The effects on the calcium oxalate urolithiasis urinary risk factors of Herniaria hirsuta L. (Carryophyllaceae) and Agropyron repens L. (Gramineae), in herb infusion form, combined with different diets (standard, high glucidic, high protein) have been studied using Wistar rats. From this study it is deduced that the possible effects of the A. repens infusion can not be assigned to any positive effects on the main urolithiasis risk factors. The tentative antilithiasic effects of the H. hirsuta infusion clearly depends on the diet. Thus, a clear increase in the citraturia was only detected when such infusion was administered with the high protein diet.