Miscibility of blends of nylon 46 and ethylene-co-vinyl alcohol copolymer (EVOH) was investigated. Blends were prepared by casting from formic acid. Miscibility of the blends was investigated by means of Fourier transform infrared (FTi.r.) spectroscopy and thermal analysis. Tensile properties of the nylon 46/EVOH blends were measured using a tensile tester. Based on optical clarity and melting temperature behaviours, it was shown that the nylon 46/EVOH blends are miscible at concentrations below 35 wt% of nylon 46. The blends having less than 35 wt% of nylon 46 showed strong intermolecular interaction between the C-O group of EVOH and the N-H group in nylon 46. X-ray diffraction (XRD) studies showed that the crystalline structure of nylon 46 was altered when the blend composition is 35/65 nylon 46/EVOH by wt%.