Calcium oxalate is the most important constituent of urinary calculi and the excretion pattern of calcium and oxalate is not consistent with stone formation. The increase in urinary calcium and oxalate in calcium oxalate stone formers has been found to be associated with the increase in uric acid and uromucoids along with the increase in inorganic phosphate and magnesium (in adults only) whilst citrate was decreased (in children only). The role of uric acid and uromucoids in the genesis of calcium oxalate stone is indicated.