Flat membranes composed of blends have been studied in the treatment of wastewater due to the influence on their properties. The objective of this study is to develop flat membranes from pure polymers and polymeric blends of polyestersulfone/polysulfone, improving morphology and permeability, making them suitable for the treatment of oily waters. Initially, it was investigated the interaction between the two polymers from the analysis of spectroscopy in the infrared region with Fourier transform (FTIR) of pure polymers and of membranes produced from the blends. The influence on the hydrophilicity of the compositions was observed by altering the contact angle of the membranes produced. By X-ray diffraction (XRD), the similarity between the Psf and PES bands was perceived. Subsequently, the flat membranes were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and flow measurements, revealing that the different concentrations of the blends modified the morphology and water permeate flow of the membranes. By turbidity analysis, it was possible to visualize percentage that up to 99.5% of oil was removed.