The present study was designed to evaluate the anthelmintic potential of leaves & shoots extract of Uncaria gambier Roxb. The alcoholic extract of Uncaria gambier Roxb. & its ethyl acetate fraction at different concentrations (25, 50, 75, 100 mg/ml) were tested on Indian adult earthworms (Pheretima posthuma) by in vitro standard procedure. Time of paralysis and time of death of the worms were considered as the parameters to assess the anthelmintic action. Albendazole and 2% w/v gum acacia in distilled water were used as standard and control respectively. The ethyl acetate fraction of alcoholic extract exhibited potent anthelmintic activity compared to alcoholic extract as evidenced by significant decrease in time of paralysis & death. The observed activity could be due to the presence to phenolic compounds, particularly flavonoids in the test extract. These in vitro studies indicated that the Uncaria gambier Roxb. is a significant source of natural anthelmintic, which might be helpful in preventing the progress of various parasitic disorders.