The present study evaluation of effect of Rosmarinus officinalis L. on ethylene glycol induced kidney stone in rats showed that the ethanolic extract of Rosmarinus officinalis possess the diuretic activity and effective in the treatment of kidney stone. The activity was evaluated against ethylene glycol (0.75%) induced kidney stone in albino rats. Animals were divided into five groups, containing six animals in each. Group I serve as normal control and received regular rat food and drinking water ad libitum. Ethylene glycol (0.75%) in drinking water was feed to Groups II to V for induction of renal calculi for 28 days. Group III received standard anti-urolithiasis drug, cystone (750mg/kg body weight) from 15th to till 35th day. Group IV and V received ethanolic extract of Rosmarinus officinalis at dose of 100mg/kg and 200mg/kg respectively from 15th to till 35th day.
 The serum creatinine level, serum urea level, urine calcium level, protein level in urine, serum uric acid was increased and serum calcium level, protein level in serum was decreased in all experimental groups except normal control group after ethylene glycol administration till day 14.
 The animals treated on the day 14th with standard drug (Cystone 750mg/kg) and Rosmarinus officinalis extract (100mg/kg and 200mg/kg), were observed significant decreased serum creatinine level, serum urea level, urine calcium level, protein level in urine and serum uric acid and increased serum calcium level, protein level in serum compared to normal control group on the day 28th and 35th.
 This indicates that the ethanolic extract of Rosmarinus officinalis (200mg/kg) have protective role against kidney stone.
 Keywords: Kidney Stone, Ethanolic extract, Rosmarinus officinalis, Ethylene glycol, uric acid, creatinine.