10.22376/ijpbs.2019.10.1.p1-12 Volume 1 Issue 4 2010 (October - December) The methanol extract of the tuber of lessThan i greaterThan Amorphophallus paeoniifolius lessThan /i greaterThan was studied for its lessThan i greaterThan in-vivo lessThan /i greaterThan analgesic activity by using the tail-flick method and the acetic acid induced writhing response in mice. The safety of extract in animals was confirmed from the acute toxicity studies. The time course study was performed to find the peak time for the maximum analgesic activity. The effective dose of the extract for analgesic activity was calculated from dose-response curve by using the tail flick and acetic acid induced writhing method. In both of the cases diclofenac sodium was used as standard drug. In both of tail flick method and acetic acid induced writhing response method; the intra-peritoneal administration of methanol extract of lessThan i greaterThan Amorphophallus paeoniifolius lessThan /i greaterThan tubers (250, 500 mg/kg) induced a significant analgesic activity in a dose-dependent manner. The plant may have the phytoconstituents which inhibit cyclooxygenase enzyme or act on central opioid receptors (µ receptors). Yadu Nandan Dey,Shankhajit De,Ajoy Kumar Ghosh Amorphophallus paeoniifolius, acute toxicity study, analgesic activity, writhing response. 662-668