Solution pH plays an important criterion in the biosorption system in ensuring optimum uptake of heavy metal by a biomass is achieved at the highest performance. In this study, the biosorption of lead (II) ions by the non-living biomass of P. amaryllifolius Roxb is performed at various pH from acidic to alkaline conditions. Results show that the optimum pH for the removal of lead (II) ions from wastewater occurs at pH 5, whereby the sorption activity occurs through monolayer process as it follows the Langmuir isotherm. High removal percentage of the metal ions at various concentrations further emphasize on the viability of P. amaryllifolius Roxbto be utilized as a green resources in the wastewater treatment. © 2014 Trans Tech Publications, Switzerland.