Objective: The study was designed to evaluate antipyretic activity of ethanolic and aqueous extracts of seeds of Caesalpinia crista linn. in various experimental animal models. Material and methods: After collection of seeds, ethanolic and aqueous extract were prepared and the phytochemical screening was performed. Then ethanolic and aqueous both extracts of Caesalpinia crista linn. were evaluated for antipyretic activity using Brewer’s yeast induced pyrexia in rats, TAB-vaccine induced pyrexia in rabbits and Boiled milk induced pyrexia in rabbits models. The differences between the temperatures were recorded. Results and Discussion: The preliminary phytochemical screening of the ethanolic and aqueous extracts of the plant Caesalpinia crista linn. showed the presence of phytoconstituents such as Flavonoids, Tannins, Proteins, Alkaloids, Carbohydrates Reducing Sugars, Phytosterols, Saponins and Triterpenoids. After the administration of extracts, when the rectal temperatures were compared with 0 hour temperature at a time interval of 1 hour for six hours, there was a significant decrease in the temperature by the plant extracts and the standard drug (Paracetamol). Flavonoids are known to target prostoglandins which are involved in the late phase of acute inflammation, pyrexia and pain perception. Flavonoids reduce lipid peroxidation by preventing or slowing the onset of cell necrosis and by increasing the vascularity. The anti-pyretic action of Caesalpinia crista linn. may be due to the inhibition of prostaglandin synthesis. Conclusion: The study shows that ethanolic and aqueous extracts have antipyretic activity, but the ethanolic extract shows more significance then aqueous extract.