Leucaena biomass waste was used for preparation of activated carbon by chemical activation using KOH and pyrolysis in a muffle furnace at 800 degrees C for 30min. Leucaena activated carbon (LAC) as a sorbent material was used for removal of Cu (II) and Pb (II) ions from aqueous solutions. The present study reveals that LAC is efficient sorpent, fast kinetics, as easy to handle, and small amount of secondary sludge produced. The isotherm, kinetics, and thermodynamics of Cu (II) and Pb (II) sorptions by LAC were investigated. The isothermal data were found to be correlated with the Langmuir model better than the Freundlich model. The maximum sorption capacity (Q(0)) for the studied sorbent toward Pb (II) and Cu (II) was 32.18 and 7.89mg/g, respectively. The experimental data show that the external diffusion and intra-particular diffusion are significant in the determination of the sorption. The thermodynamic parameters indicated that the sorption processes were spontaneous and endothermic in nature.