In this work, morphological, electrical, and dielectric performance of nylon copolymer (PA6, 66)/ethylene propylene diene rubber (EPDM) blends were systematically studied with reference to blend ratio and compatibilisation. As the concentration of PA6, 66 and the percentage of compatibiliser in the blend increases the resistivity values decreases. The existence of two phases, PA6, 66 and EPDM with different conductivity and interfacial polarization are responsible for the increase in the dielectric properties of the blends. Compatibilisation of the blends improved the dielectric constant of the blend system. Addition of 2.5% of compatibiliser gave the highest value of dielectric constant. At a high concentration of EPM-g-MA, the polarity of the compatibilised blends was found to be increased, which resulted in the substantial increase in the value of loss and dissipation factor. The dielectric values of the blends were correlated with blend phase morphology. Finally the experimental data was compared with various theoretical predications. POLYM. ENG. SCI., 2019. (c) 2019 Society of Plastics Engineers