The paper reports on the preparation, structure and properties of ternary thermosetting blends, based on DGEBA epoxy, cured with 3,3'-DDS and modified by the addition of CTBN reactive liquid rubber and/or 0.3 wt% of commercial multi-walled carbon nanotubes. The toughening effect of the phase-separated rubber particles is enhanced by the presence of the nanotubes, through a change in the morphology. In the absence of the rubber, the nanotubes alone produce a minimal effect upon the thermo-mechanical characteristics of the resin. However, the electrical conductivity of the cured resin samples is found to increase by five orders of magnitude, up to 3.6 x 10(-3) S/m in the ternary blend.