Electro-conductive polymer nanocomposites have been intensively used as a new structural and functional materials over last decades. They possess all benefits of light, easy to produce and cheap polymer materials, combined with advanced electrical and structural properties. Electrical percolation in carbon particle filled rubbers is well known phenomena, but only recently it has been shown, that at certain concentrations of conductive filler, these composites exhibit remarkable mechano-electrical effects (piezo- and tenzo-resistivity). In our work we have used polyisoprene – nanographite composites (PNGC) as a hyperelastic piezoresistive material for elaboration of soft pressure sensors. As excellent conductive filler different nanographite powders have been proved for sensitive composite material. They were: graphitized high structured carbon black, carbon nanotubes and thermo-exfoliated graphite flakes as well. Such sensors can be made in different sizes and shapes so they can be easily tailored to meet specific requirements. They are proved to be functional for uni-axial operational pressures up to 1 MPa and can be successfully used in different industrial and engineering applications, like civil security, industrial monitoring, robotics, traffic surveillance and many more. In this work we reveal the basic concepts, necessary to successfully obtain piezoresistive PNGC, as well as to investigate their mechano-electrical properties. We propose the concept of entirely hyper-elastic piezoresistive pressure sensor element, which can be made from rubbery structural parts only, thus providing outstanding mechanical integrity and resistance to mechanical impacts.