An attempt to modify membranes for direct methanol fuel cells by blending Nafion(R) with a (vinylidene fluoride)-hexafluoropropylene copolymer (VDF-HFP copolymer) from their solutions is reported. The purpose of this work was to reduce the methanol transport while still retaining the essential proton conductivity in a water-containing environment. The apparent conductivity, methanol barrier property, and equilibrium contact angle as a function of the membrane compositions are discussed. The blend membranes were also investigated using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Compared with the pure Nafion(R) membrane, the Nafion(R)/VDF-HFP copolymer blend membrane with 62.5 vol % of the VDF-HFP copolymer shows a decrease in the apparent conductivity by about 2 orders of magnitude, and the methanol barrier properties increase substantially when only 25 vol % of the VDF-HFP-copolymer is incorporated. The equilibrium contact angles of water drops on the Nafion(R)/VDF-HFP copolymer blend membranes as a function of the VDF-HFP copolymer content are rather similar to the plot of the advancing angle versus the percentage of the lower-surface-energy phase. X-ray diffraction studies indicate that these two polymers crystallize separately when blended and cast from their solutions, and the crystallization behavior is equivalent to that of the unblended state. DSC reveals that when the VDF-HFP copolymer is mixed with Nafion(R) in their solution forms, an interdiffusion or other interaction takes place at the interfaces between their noncrystalline regions.