The methanol extract of root stocks of Polygonum glabrum Willd (MEPG) belonging to family Polygonaceae, was evaluated anti pyretic activity. The antipyretic activity was studied using Brewer‘s yeast induced hyperpyrexia method in Wister strain albino rats. The methanol extract at a dose of 200mg/kg & 400mg/kg were evaluated for antipyretic activity. The extract of Polygonum glabrum plant showed a significant (P<0.01) dose dependent antipyretic effect in yeast induced elevation of body temperature in experimental rats. Phytochemical screening of the extract revealed the presence of alkaloids, flavanoids, and phenolic compounds. The results showed that the extract contains some pharmacologically active principles and lend pharmacological credence to the ethanomedical use of the plant in the management of pyrexia and it shows significant antipyretic activity when compared with the standard drug. So it can be recommended for further studies.