¹United Institute of Pharmacy, A 31/1, UPSIDC, Industrial Area Naini, Prayagraj 211010, India DOI : 10.29228/jrp.173 The plant Euryale ferox salisb family (Nymphaeaceae) commonly known as prickly water lily have been traditionally used in the treatment of rheumatism hence in the present study, investigation of anti-arthritic activity was accomplished using 50% v/v unproccessed ethanolic extract of leaves & chloroform fraction in arthritic models. The 50% ethanolic extract (EFEE) was separated into four fractions including n-hexane (EFHF), chloroform (EFCF), ethyl acetate (EFEA) and methanol (EFMF). Preliminary phytochemical screening and TLC were carried out on extract and all four fractions. The induction was accomplished by intraplantar injection of formaldehyde (2%v/v), turpentine (10%v/v) and complete Freund’s adjuvant (CFA) in left hind paw of wistar albino rats. Evaluation of anti-arthritic potential was been done by considering paw volume, body weight, joint diameter, arthritic score, serum enzymes, blood parameters and histopathological examination of rats blood and tissues. Extract and fraction were tested by phytochemical screening which signifies the existence of steroids, flavonoids, amino acid, alkaloid and phenolic compounds. In acute and chronic arthritic models, the plant had a dose-dependent anti-arthritic effect. The chloroform fraction (200mg/kg b.w) had a more significant effect than the 50% ethanolic extract. Hence, Euryale ferox ameliorates hematological indices, body weight, and histopathological alterations in a significant way. Keywords : Antiarthritic; Arthritic score; Complete Freund’s adjuvant; Euryale ferox salisb; Histopathology