Multi-walled carbon nanotubes (MWNTs) were incorporated in electrospun Nylon 610 fibers. The MWNTs used were synthesized by a thermal CVD method. To eliminate metallic catalyst residues in as synthesized MWNTs, they were treated in HNO3 and HCl. The potential adhesion between the MWNTs and Nylon 610 was expected by the interaction between the amide group of Nylon 610 and the oxygen-containing species on the MWNTs such as carboxylic acid group introduced during the purification step. Contrary to the previous works on electrospinning using a simple blend of carbon nanotubes with polymeric materials, we incorporated MWNTs as nanoscale fillers by in-situ interfacial polymerization. We also investigated morphology of the electrospun Nylon 610 fibers with MWNTs.