This article reports the effect of functionalized multiwall carbon nanotubes (MWNT-COOH) on the morphological, dynamic mechanical, mechanical and thermal properties of polyetherimide (PEI)/liquid crystalline polymer (LCP) (Vectra A950) blends. The chemical modification of carbon nanotube enhanced the compatibility and the miscibility between PEI and LCP in the composites. Addition of functionalized MWNTs into the blend improved the thermal, mechanical and dynamic mechanical properties of the composite due to the presence of strong interfacial interaction between the polymer matrixes and the nanotubes in polymer composites. The glass transition temperature (from tan delta) increased from 208 degrees C to 245 degrees C with the addition of 1.8 wt% functionalized MWNTs in the blend of PEI/LCP. The tensile strength of the composite with 1.8 wt% MWNT-COOH was enhanced by 61% and 44% as compared to PEI/LCP blend and pure PEI. The functional groups on the MWNTs surface played an important role in accelerating both the dispersion of MWNTs and the interfacial adhesion in the composites compared to raw MWNTs.