Recently, explorations on nanocomposite materials have received much recognition in the field of material science and engineering. Commercialization of various classes of conducting nanofillers is growing, yet achieving their full technological potential will hinge on the ability to engineer nanofiller with controllable and well-defined properties. The anisotropic conducting particles have excellent electrical properties and unique geometry that can increase the bulk conductivity of typical engineering polymers by ~1010–1014 Sm−1 at very low filler concentration. Nanofillers with good electrical properties are used for the fabrication of novel polymer nanocomposites designed for electrostatic discharge and electromagnetic interference (EMI) shield protection, field emission gas sensor, and fuel cell applications. The properties of polymer matrix like mechanical strength, thermal stability, electric/dielectric, antioxidant, and barrier properties are greatly enhanced by the nanofiller. However, in addition to the in vitro and in vivo studies, more randomized trials are required to justify the applications of these promising materials. This book chapter paid special attention to the types, general and electrical properties of nanofillers, and their influence on polymers.