The conventional strain sensors, e.g., resistive and optical strain gages, established in the market, are deployed in different environments and structures, providing the flexibility of integration with different measurement systems. However, they require a local energy source to work or cables, limiting their use in some scenarios such as moving parts of machines. The SAW (Surface Acoustic Wave) devices can be used as piezoelectric strain sensors since they have sensitivity to strain, can operate passively by antennas and can be integrated to wireless monitoring systems. Its working principle is based on surface acoustic waves generated on piezolectric medium. The stress state of the medium changes the characteristics of these waves and induces changes in the operating frequency. The present work analyzed the strain sensitivity of SAW resonators made of ST-X cut quartz operating at a central frequency of 433,92 MHz, bonded with different adhesives, and tested their operation as passive wirelesss sensors. The methodology included non-destructive tensile testing at different temperature, and also finite elements simulations. The experimental results showed linear relation between the frequency change and the applied strain, agreeing with the literature. The wireless interrogations was successful, confirming the great potential of this technology. The numerical results, combined to a theoretical model, matched well the experiments, validating the model.