Piezotronics can not only afford control of electronic transport over potential barriers, but the attendant mechanical stress can also influence various physical properties of piezoelectric semiconductors. Stress significantly affects the optical properties of these materials as well as their response toward the chemical environment and magnetic fields. This article focuses on the utilization of piezotronics with regard to these physical parameters for sensor applications. Stress sensors, optical sensors (especially in the ultraviolet range), and sensors for chemicals in gas and liquid phases or magnetic fields via coupled magnetostrictive layers are discussed. The benefits of piezotronics for sensors are highlighted by discussing respective figures of merit.