MgAl2O4 nanopowder has been prepared by alkoxides hydrolysis with further calcination at temperature of 700 degrees C. The adsorption of a leather dye, Direct Black 38, onto this material was investigated. The sample was characterized by X-ray-diffraction (XRD), N-2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy. The results showed that sample present a pure phase, and the average nanocrystal size of 8 nm, the BET surface area is about 206.5 m(2) . g(-1) and total pore volume is about 1.44 cm(3) . g(-1). Adsorption kinetics data were modeled by film and pore diffusion model. The experimental isotherm was described by the Langmuir model. MgAl2O4 nanopowder presented a great removal efficiency of leather dye by adsorption process, with a maximum adsorption capacity of 833 mg of dye per gram of adsorbent.