In this study, novel ultrafiltration (UF) polyacrylonitrile (PAN) based nanocomposite membranes, containing goethite nanoparticles (NPs), were fabricated for copper ions (Cu(II)) adsorptive removal from aqueous solutions. First, goethite NPs, with diameter up to 50 nm, were synthesized. The next step was fabrication and evaluation of the nanocomposite membranes with the embedded NPs in it. The optimum compositions for the fabrication of the membranes were determined using response surface methodology (RSM) based on Box-Behnken design (BBD), at which the effect of membrane composition, on the metal ion removal and water permeability was studied under constant operating conditions. The evaluated variables were PAN concentration (15-18%), polyvinylpyrrolidone (PVP) concentration as an additive (1.3-1.5%), and loading percent of the NPs (0.0-0.5 wt%). The optimum conditions, at which the maximum ion removal and the maximum water permeability were achieved, were 15%, 1.3% and 1.0% for PAN, PVP, and NPs loading, respectively; at this point, the highest Cu(II) ions removal was 49.1% and the maximum water permeability was 285 LMH/bar. These values confirmed the experiments and the predicted values by the model which were 47.6% and 268 LMH/bar, for removal and water permeability, respectively.