This chapter describes the piezoelectric (PE) transducers, the mechanical parts of piezoelectric accelerometers with integral electronics (IEPE). The function of the PE transducer in an IEPE accelerometer, its transfer function, equivalent electrical schematic, main electrical characteristics, construction, and types are described. Three basic types of PE transducers used in IEPE accelerometers, compression, shear, and flexural, their advantages and drawbacks are presented. Topics also include description of the piezoelectric (crystal) elements, the primary sensitive elements used in IEPE accelerometers. Two most popular piezoelectric element materials used in IEPE sensors, quartz and lead zirconate titanate (PZT) piezoceramic, their advantages and drawbacks are presented.