Urolithiasis is a chronic disease that has affected human kind from last so many centuries. In this disease pain gets precipitated due to the calcium oxalate stone in kidney or in any part of urinary tract. Perfect causes for urolithiasis are not known, but age, sex, diet, life style, medical history, family history, etc are responsible for it. From the ancient time people have been using plants and animal sources as a medicine. There are so many plants which are having an antiurolithiatic activity. This study proves that the aqueous extract of Couroupita guianensis Aubl has a capability to dissolve calcium oxalate crystal in in vitro conditions when it is compared with cystone as a standard. The antiurolithiatic activity of Couroupita guianensis Aubl leaves is probably mediated through the inhibition of Calcium oxalate crystallization. In addition to its free radical scavenging and antioxidant activities, it acts as an excellent agent for the prevention of urolithiasis.