In Morocco, Ziziphus lotus is commonly used as an urolithiatic agent in the traditional medicine. To confirm this effect, an aqueous extract of Ziziphus lotus (AEZL) has been studied in ethylene glycolinduced urolithiasis model of rats. 30 male rats were randomly divided into five groups of six animals each. Group I served as a vehicle control and received distilled water (0.5 ml/100 g p.o.). All remaining groups received calculi inducing treatment for 28 days, comprised of 0.75% v/v ethylene glycol with 1% w/v ammonium chloride in drinking water ad libitum for 3 days followed by only 0.75% v/v ethylene glycol for 25 days. Group II served as lithiatic control and received distilled water (0.5 ml/100 g p.o.). Group III served as curative treatment group and received AEZL at doses of 150 mg/kg from 14th day to 28th day. Group VI served as preventive treatment group and received AEZL at doses of 150 mg/kg from 1st day to 28th day. Group V served as therapeutic and received a drug "Cystone" at dose of 750 mg/kg from 14 th day to 28 th day. The extract treatment decreased the levels of oxalate and calcium in urine. Crystalluria analysis showed that untreated rats excreted large CaOx monohydrate and few dihydrate crystals while treated animals excreted mostly small CaOx dihydrate crystals. Significant similarity was observed between preventive and therapeutic anti-urolithiatic effect of AEZL and anti-urolithiatic effect of cystone (P<0.001). These results demonstrated that AEZL have an anti-urolithiatic effect with preventive and therapeutic treatments in this experimental condition.