In this study, a polyacrylic acid-co-butyl methacrylate/Fe3O4 nanocomposite was In this study, a polyacrylic acid-co-butyl methacrylate/Fe3O4 nanocomposite was prepared using in-situ coprecipitation polymerization technique, for the adsorptive removal of methylene blue (MB) dye from industrial wastewater. Chemical structure of the prepared magnetic nanocomposite was confirmed using Fourier transform infrared spectroscopy (FTIR). Thermal properties were studied using thermal gravimetric analysis (TGA), while the morphological structure was examined using a scanning electron microscope (SEM). Different parameters affecting the adsorption process, such as contact time, pH, adsorbent dosage, agitation speed, and initial dye concentration, were also studied. This study indicated that the percentage removal of MB dye has decreased with increasing initial dye concentration while increased with raising the agitation speed from 100 to 300 rpm. Additionally, studying the pH profile of the dye solution shows that the highest MB removal percentage (98%) was recorded at pH 3.5. These results demonstrated that the prepared magnetic nanocomposite could be considered as a promising adsorbent for the removal of MB dye from industrial wastewater.