Melt compounding was used to produce compounds with Nitrilerubber (NBR) and hydrogenated Nitrilerubber (HNBR) as matrices with various Nitrilecontents (ACN) and Multi-Walled Carbon Nanotubes (MWCNTs) as fillers. Further these were tested to determine their mechanical and thermo-mechanical properties. In Phase I these materials were filled with the same type and amount (30 phr) of MWCNTs. To examine the compounds (thermo-)mechanical properties following tests were used: Tensile Test, Dynamical-Mechanical Analysis (DMA), Differntial Scanning Calorimetry (DSC), Shore A Hardness and Density. Depending on the matrices (ACN-content) various improvements could be discovered. The stress at break value for the best compound was improved by 400 % and reached 27 MPa at 200 % elongation at break (elongation at break unfilled rubber: 400 %). In Phase II the matrix showing the best performance was further used to determine the influence of either the MWCNT-type and compatibilisation (uncompatibilised, hydroxyl- and carboxy-compatibilised). As in the first phase melt compounding was used to produce the materials. A significant increase of the mechanical properties could be measured at small amounts of filler (1.2 phr). For the compound with 30 phr hydroxyl-compatibilised MWCNTs a tremendous stress at break value of 25 MPa was found (increase of 400 % compared to the unfilled rubber) by a decrease of the elongation at break of just 25 % (from 400 % for the unfilled to 300 %). A strong dependence of the values of hardness, density and glass transition on the amount of filler could be deduced. In contrast no significant impact of the different compatibilisations could be measured.