AbstractSurface roughness and sharkskin of extruded polymers, including blends are affected by the morphology and processing conditions. In this study, different effects on the roughness of the polymer blend extrudates were investigated. Co-continuous poly(ethylene) oxide/ethylene-vinyl acetate (PEO/EVA) blends with three different molecular weight (Mw) PEOs were compounded successfully. It was found that the better co-continuity of the structure and smoother surface were achieved for lower Mw PEO/EVA blend because of more effective stress transfer in the PEO phase. The effect of processing temperature was also studied with decreasing processing temperature reducing the surface roughness of the high Mw PEO/EVA blend, which was also achieved as a result of improved co-continuous morphology by adjusting the viscosity and elasticity ratio with shifting temperatures.