Investigations were undertaken to study the role of lupeol, a pentacyclic triterpene from Crataeva nurvala stem bark, in calcium oxalate experimental rat urolithiasis. A 2% solution of ammonium oxalate was administered by gastric intubation for inducing hyperoxaluric condition in adult male rats of Wistar strain. The duration of treatment was for 15 days. This resulted in increased urinary excretion of oxalate associated with reduction in citrate and glycosaminoglycans. The urinary marker enzymes which indicate renal tissue damage namely--lactate dehydrogenase, inorganic pyrophosphatase, alkaline phosphatase, gamma glutamyl transferase, beta-glucuronidase and N-acetyl beta-D glucosaminidase were found to be elevated. Lupeol administration (25 mg/kg body weight/day) reduced significantly the renal excretion of oxalate. It also reduced the extent of renal tubular damage as evidenced from the decreased levels of the above enzymes in urine. Such a reduction is likely to be beneficial in minimizing the deposition of stone-forming constituents in the kidney which provides antilithic effect.