Huge amount of oily wastewater is annually discharged from several activities such as oil refineries, chemical and petrochemical industries. Several methods are employed for the treatment of oily wastewater including physical, chemical, and biological techniques in order to minimize the harmful impacts before being reused. The present study compares the treatability among three different types of nanoparticles NPs (MCM-41, MWCNT and BaFe2O4) to remove oil content from real oily wastewater discharged from refinery process under the effect of the operational variables which are the dose of the effective NPs (0.025-0.10 g), agitation speed (100-250 rpm), and the contact time (5-120 min) using batch-scale. RSM design method and Minitab program were performed to design the experiments and to estimate the mathematical correlations and the optimum values of the operational variables. Various devices were employed to test the properties of nanoparticles such as X-ray diffraction, SEM and FTIR. The results revealed that the (MCM-41) type possesses the higher treatability in comparison to other types. Moreover, the Langmuir isotherm gives a better fit than the Freundlich isotherm model. The optimum values of the operational parameters obtained were 0.063g, 162rpm and 120min for the dosage of MCM-41 NPs, agitation speed and the contact time respectively. The oil content removal efficiency at these conditions of the optimum values was 98.3% as observed which proofs the treatability of MCM-41 NPs in case of real oily wastewater.