Electroless plating was used to prepare nickel coated mica fillers. To optimise the conductivity of the filler the nickel coating needed to exceed a certain weight percentage, depending upon the particle size of the mica, and cover the surface of the mica particles. Treatment of the filler in hydrogen improved its conductivity considerably. The fillers were incorporated into an ABS resin to prepare composites as potential electromagnetic interference shielding materials. Increasing the particle size of the mica reduced the critical filler loading required to produce electrically conductive composites. Reducing sample thickness caused a decrease in resistance, due to changes in filler orientation.