10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 1 2014 (January - March) To study the anti-inflammatory activity of a hydro-ethanolic extract of lessThan i greaterThan Alternathera brasiliana lessThan /i greaterThan leaves (HEAB).The study was carried out using Wistar albino rats (150-180 gm) and Swiss albino mice (20-25 gm) of either sex. HEAB was prepared by cold maceration. The effect of HEAB was investigated for anti-inflammatory activity using carrageenan induced paw edema (acute), cotton pellet granuloma (sub-acute) and formaldehyde induced arthritis (chronic) method. The analgesic activity of HEAB was studied using formalin induced paw licking. Statistical analysis was done by using One-way analysis of variance (ANOVA) followed by post hoc Dunette's test. p lessThan 0.05 was considered statistically significant.The anti-inflammatory activity of HEAB (100, 200 & 400 mg/kg, p.o.) showed significant (p lessThan 0.05) decrease in carrageenan induced paw edema. In sub-acute model HEAB (200 & 400 mg/kg, p.o.) significantly decrease the granuloma formation. In chronic model, HEAB (100, 200 & 400 mg/kg, p.o.) the arthritis was significantly lowered. HEAB did not show any significant effect in early phase of formalin paw licking while it significantly decrease the paw licking in late phase at given doses.HEAB showed significant anti-inflammatory activity. SACHIN KUMAR AND CHANDANA C. BARUA AND SUKIRTI DAS Inflammation, Hydro-ethanolic extraction, Cold maceration, OECD. 33-41