Neat and compatibilized high density polyethylene and ethylene vinyl acetate blend membranes were fabricated via thermally induced phase separation method. ATR-FTIR results confirmed that existence of PE-g-MA as compatibilizer keeps EVA molecules in the bulk of the membrane. Phase behavior studies showed that addition of compatibilizer improves the compatibility of the blend; therefore any cloud point was observed. Leafy structure obtained by SEM images also confirmed that a solid-liquid phase separation was occurred for all ranges of blending ratios. Pure water flux (PWF) and porosity analyses showed that compatibilized HDPE/EVA blend membrane with EVA content of 10 wt.%, exhibits the best results in which PWF increases more than 2.8 folds in comparison with both neat blend and pure membranes. The results show that the tensile strength as well as elongation at breaks for compatiblized blend membrane is improved. The fouling behavior of compatiblized blend membranes with optimum composition of EVA in BSA protein filtration showed that maximum flux recovery of 71%, which was 18% and 86% higher than that of neat blend and pure HOPE membranes, respectively. Addition of compatibilizer decreased the portion of irreversible fouling ratio and increased the portion of reversible fouling ratio. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.