Polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) solutions incorporated with multi wall carbon nanotubes (MWCNTs) and NiZn ferrite (Ni0.6Zn0.4Fe2O4) nanoparticles were electrospun at various weight percentages, and then thermal conductivity values of these nanocomposite fibers were determined using a comparative method. During the electrospinning process, system and process parameters, such as concentrations, applied voltage, tip-to-collector distance, and pump speeds were optimized to receive the consistent nanocomposite fibers. Polymer composites with high thermal conductivities are required in many applications, such as electronic packaging, satellite devices, charging/discharging, energy dissipation, and low thermal expansions. The presence of conductive filler materials in polymers increased the thermal conductivity of MWCNTs-based fibers over 10 fold, which may be attributed to higher thermal conductivities of these filler materials. The electrospun fibers incorporated with NiZn ferrite did not show similar improvement.