The aim of the study was to assess the influence of the polymer molar mass on the properties of polymeric membranes produced with the addition of carbon nanostructures (commercial graphene oxide, GO). The membrane support layer was made from polysulfone (PSU) dissolved in dimethylformamide (DMF). The polymer matrix was formed from polyvinylidene fluoride (PVDF) dissolved in dimethylacetamide (DMAC). PVDF, serving as the base polymer, was purchased in two different physical forms, i.e granules with a molar mass of 530,000 g/mol and powder with a molar mass of 534,000 g/mol. The membranes were prepared via wet phase inversion, with or without the addition of GO to volume of the polymer matrix. The experiments helped to determine the thickness, tensile strength and contact angle of the produced membranes. Hydrodynamic studies allowed calculating the volumetric permeation flux and total resistance of both the reference membranes and the membranes containing GO was evaluated using a laboratory OSMONICS KOCH ultrafiltration unit.