This paper presents a nanocomposite strain gauge composed of poly(dimethylsiloxane) and multi-walled carbon nanotubes. Possessing excellent mechanical and piezoresistive properties, the biocompatible nanocomposites could withstand large strains repeatedly, which is desirable for miniaturized implantable biomedical devices. Prototype strain sensor was fabricated with simplicity and efficiency via microcontact printing and cast molding. Experimental results revealed sensitive response of resistance with regard to change of tensile strains. Multiple cycles of stretching and relaxing of device revealed consistent and repeatable measurements. An interesting hysteresis phenomenon was also observed. With further investigation of the elastomeric mechanisms, this strain sensing technology could yield promising potentials in many biomedical applications.