||Carbon black (CB), a low cost conductive nanofiller, incrementally substituted the single-walled carbon nanotube (SWNT) in polypropylene (PP) composite to explore the effect on electrical conductivity. The CBs and SWNTs can impart electrical conductivity to PP by creating conductive paths over short and long distances, respectively. 2.0wt% of CNT was gradually substituted with carbon blacks with CNT:CB compositions (10:0, 7:3, 5:5, 3:7, 0:10). The electrical, mechanical and rheological properties of the tertiary composites were evaluated. 5:5 CNT/CB composition exhibited the synergistic effect on electrical conductivity with enhanced mechanical properties exceeding the mono filler composites while other compositions were on par.