The use of rubber-seed shell, an agricultural waste by-product as a raw material for the production of activated carbon with chemical activation using potassium hydroxide, KOH was investigated. In this work, the produced activated carbons were characterized by Nitrogen Adsorption Theorem and Scanning Electron Microscope instruments. The optimal activation conditions were found at temperature of 500°C and at activation time of 180 min. Result showed that the BET surface area, total pore volume and diameter of the activated carbon were 1288.52 m 2 g -1, 0.81 cm 3 g -1 and 2.49 nm, respectively. From the nitrogen adsorption-desorption isotherm and pore size distribution, it was found that vast majority of pores fall within range of mesopore, therefore indicating that activated carbon prepared from rubber-seed shell is an attractive source for liquid and gas adsorption applications. © 2012 Asian Network for Scientific Information.