In this study nano-modified epoxy adhesives using carbon nanofillers have been investigated. The epoxy mixture used in this work is based on the tetraglycidylmethylenedianiline TGMDA and the epoxy monomer 1-4butanedioldiglycidyl ether (BDE), that acts as a reactive diluent. The 4,4-diaminodiphenyl sulfone (DDS) is used as curing agent. These components were supplied by Sigma Aldrich. Moreover, the liquid rubber carboxyl-terminated butadiene acrylonitrile copolymer (CTBN Hycar-Reactive Liquid Polymers, Mn = 3600 containing terminal carboxy groups) is also employed. The epoxy adhesive was prepared by adding 12.5 phr of CTBN and 10 phr of triphenylphosphine to the epoxy TGMDA in the liquid state. The epoxy mixture is then mixed with BDE monomer at a concentration TGMDA/BDE of 80%:20% wt/wt. This particular epoxy formulation has proven to be very effective for improving nanofiller dispersion due to a strong decrease in the viscosity. The MWCNTs (3100 Grade purchased from Nanocyl S.A.) were incorporated into the TGMDA-CTBN-BDE-DDS blend by using an ultrasonication Hielscher model UP200S-24 kHz. The rheological measurements in the liquid state, before curing, were carried out on a Physica-MCR301 (Anton-Paar) rotational rheometer equipped with a parallel plate geometry. Small amplitude oscillatory shear measurements, within the linear viscoelasticity regime, on the TGMDA-CTBN-BDE-DDS blend and on the mixtures with 0.1, 0.5 and 1 wt% of MWCNT content were performed at different temperatures. The inclusion of 0.5 wt% MWCNT increases the complex viscosity of the uncured dispersions of about 2 orders of magnitude at low frequency while the storage modulus G’ at low frequency becomes nearly independent of frequency indicating the formation of a percolation network in the nanocomposite.