The methanolic extract of whole plant of Amaranthus caudatus Linn. (MEAC), was tested for antinociceptive (using hot plate method, acetic acid writhing and tail immersion) and antipyretic (using yeast induced pyrexia) activities using mice and rats at doses of 200 and 400 mg/kg body weight. MEAC significantly (p < 0.05) inhibited acetic acid induced writhing and also significantly delayed the reaction time of mice to thermal stimulation produced by the hot plate and hot water in tail immersion test. MEAC significantly (p < 0.01) reduced fever induced by yeast. These results suggest that the MEAC has exhibited significant antinociceptive and antipyretic effects, which were comparable with standard drugs.