In this study, a novel nanocomposite based on pine leaf waste and modified kaolinite was synthesized for the first time, and its efficiency for cadmium and lead removal from aqueous solutions was evaluated. First, iron oxide magnetic nanoparticles were synthesized in the medium of pine leaf waste, and then, the magnetic pine leaf waste was cross-linked by bis-acrylamide and hybridized with activated amino silane kaolinite. Parameters of pH, initial concentration of cadmium and lead, adsorbent dose, and contact time were optimized by using the design of experiments. Maximum adsorption capacity for lead was achieved at pH = 5.5, adsorbent dose = 0.04 g, initial concentration of 80 ppm, and time of 30 min, and for cadmium at pH= 5, adsorbent dose of 0.1 g, initial concentration of 120 ppm, and time of 50 min. The maximum removal percentage was 99.42 and 99.32 for cadmium and lead, respectively.