The membranes were prepared with various concentrations of polyamide and monosodium glutamate additive for dialysis application in this work. The membranes were characterized by determining creatinine diffusive permeability and by obtaining scanning electron microscope images and thermal characteristics. The results show that a membrane prepared without additive has a thick skin layer and a nonporous sublayer. The permeation of creatinine solute does not take place due to this dense (thick/nonporous) structure. When an additive is used in membrane synthesis, the thickness of skin layer reduces and voids are present, which results in permeation of this unwanted solute through the membrane. © 2013 Copyright Taylor and Francis Group, LLC.