Application of porous magnetic materials for detoxification of pollutants from aqueous solutions has attracted great attention in recent years because of their ease of separation and enhanced efficiency. In this light, a three-dimensional (3D) porous NiFe2O4 adsorbent (PNA) having significant magnetic properties was synthesized and employed in detoxification of Pb(II) contaminated aqueous solution. The PNA was obtained by a sol-gel process using chitosan as precursor and was fully characterized by using FTIR, XRD, SEM, and EDAX analytical techniques. The surface morphology obtained from the SEM images of the PNA dearly exhibited the three-dimensional porous structure; pores were well interconnected. The kinetic mechanism was best described by pseudo-second-order and double-exponential models. The equilibrium state sorption data was best fitted to the Langmuir and Sips isotherm models. The studies dearly demonstrated that the PNA could be an efficient material for treatment of Pb(II) contaminated wastewaters.