To increase the electrical conductivity of polymer composites by a minimum filler amount, carbon nanotubes (CNTs) are a good choice as due to their high aspect ratio relative low percolation thresholds can be achieved. An excellent state of CNT dispersion is an important prerequisite to enhance the composite properties. However the distribution and dispersion of the as-produced agglomerated and entangled CNT powders during the melt processing is challenging. If the state of CNT dispersion is insufficient, the full potential, like the electrical conductivity and mechanical properties, of the CNT material is not fully accessible. During the well-known masterbatch dilution process, the CNT agglomerates are subjected to shearing twice, whereby not in all cases a better dispersion is observed as compared to direct CNT incorporation. To increase the probability to obtain polymer composites free of agglomerates we used a second filler to apply further rupture and erosion interactions onto the primary CNT agglomerates. In this investigation electrically conductive composites containing commercially available multiwalled carbon nanotubes (MWCNT) with electrical non-conductive talc or conductive carbon black were prepared using a twin-screw extruder ZE25 (Berstorff). The resulting electrical and mechanical properties were measured on injection molded parts. The evaluation indicates that the presence of both secondary nanofillers, talc or carbon black, affected the formation of the percolating MWCNT network and resulted in better nanotube macro dispersion. As a result the electrical percolation threshold is decreased to lower MWCNT contents using secondary fillers. In comparison to the direct CNT feeding method the masterbatch dilution showed a higher percolation threshold. Additionally, the improvement in dispersion was not reflected in the mechanical properties. Modulus and stress values increase with MWCNT, carbon black and talc addition, but not in a synergistic manner.