Fruits of Helicteres isora Linn., commonly called Murudsheng in India, are usually prescribed in the Indian traditional systems of medicine, especially in Ayurveda, for a variety of intestinal complaints. The antispasmodic activity was checked in vitro on guinea-pig ileum against three spasmogens, acetylcholine, histamine and barium chloride. The IC(50) for each was determined. The activity was compared with standard antispasmodic agents, atropine and diphenhydramine hydrochloride. The activity was also studied in vivo by observing the gastrointestinal motility in mice using the marker technique and the ED(50) was calculated. Acute toxicity studies were conducted on mice using the method of Weil and the LD(50) was determined. The results indicated that the fruits possess very good antispasmodic activity.