Investigations were carried out to evaluate the efficacy of the pentacyclic triterpene, lupeol and its ester, lupeol linoleate, against calcium oxalate urolithiasis in rats. Administration of a pyridoxine deficient diet containing 3% glycollic acid for 21 days led to increased excretion of stone forming constituents such as calcium, oxalate and uric acid. Crystal deposition and subsequent renal tubular damage resulted in increased excretion of the tubular enzymes alkaline phosphatase, lactate dehydrogenase, gamma glutamyl transferase, beta glucuronidase and N-acetyl glucosaminidase along with reduced fibrinolytic enzymes. A reduction in the urinary inhibitory factors magnesium and glycosaminoglycans was also observed. Treatment with lupeol and lupeol linoleate reduced the extent of tubular damage as evidenced from reduced enzymuria and minimized the excretion of stone forming constituents.