The methanolic extract of whole plant of Ceratophyllum demersum Linn. at the doses of 250 and 500 mg/kg was screened for analgesic, antipyretic and anti-inflammatory activities. Acetic acid, Brewer's yeast and Carrageenan were used to induce algesia, pyrexia and inflammation in albino rats of Wistar strain. The extract showed significant analgesic, antipyretic and anti-inflammatory activities. The presence of flavonoids in the methanolic extract may be contributed to its activities.