This paper presents the results of investigating the effect of halloysite on the thermal, mechanical and morphological properties of PEI/silicone rubber blend based nanocomposites. Novel PEI/silicone rubber filled with halloysite nanotubes nanocomposites have been prepared for various HNTs loadings with the aid of co-rotating twin screw extruder. The results obtained depict that the tensile strength, tensile modulus, elongation at break, hardness and impact strength have significantly increased with increase of HNTs loading. The thermal stability of nanocomposites has been enhanced and found to be maximum at 3 phr HNTs loading. Morphology of the tensile fractured surfaces of nanocomposites has been studied by Scanning electron microscope (SEM). The morphological studies have demonstrated an appreciable reduction in domain size of silicone rubber at 3 phr loading of HNTs and it clearly indicates the reinforcing ability of the HNTs. The interfacial and inter-tubular interactions between HNTs and polymer matrices, and formation of HNTs zig-zag structures are the main reasons for the improvement of various properties.