Abstract. Sulfuric acid treated Petai belalang (Leucaena leucocephala) leaf powder (SLLP) was used as an adsorbent for Pb(II) ions removal. The experimental adsorption parameters investigated include pH, dosage and initial Pb(II) concentration. Pb(II) removal was more favored at a higher adsorbent dosage, pH and temperature. Adsorption kinetics conformed to the pseudo-second order model while Langmuir isotherm model recorded the value of maximum adsorption capacity (q max) of 222 mg/g. The major functional groups involved in the adsorption process were identified as hydroxyl, amino and ether as revealed by the FTIR analysis. The prepared adsorbent demonstrated a potential application for efficient removal of Pb(II) ions from industrial wastewater.