A novel adsorbent, formaldehyde polymerized tamarind fruit shell (FPTFS) containing sulphonic acid functional groups was prepared and its utility for Hg(II) adsorption from water and wastewater was investigated. The kinetic and isotherm data, obtained at optimum pH value 6.0 for different concentrations and temperatures, could be fitted with the Ritchie modified second-order equation and Sips isotherm model respectively and the coefficients indicated favorable adsorption of Hg( II) on the FPTFS. The complete removal of 23.86mg/L Hg( II) from chlor-alkali industry wastewater was achieved by 4 g/L FPTFS. The reusability of the FPTFS for several cycles was also demonstrated using 0.1M HCl solution.