A thorough understanding of the ultrasound instrumentation and techniques and a better understanding of the capabilities and limitations of ultrasound equipment will enable the operator to perform meaningful two- and three-dimensional (2D/3D) endovaginal and endoanal imaging. This chapter will introduce the reader to basic ultrasound instrumentation and techniques. The ultrasound machine combines image production (2D/3D imaging) with Doppler assessment. These distinct technologies can be used independently or in combination to provide the examiner with the ability to make accurate and comprehensive diagnoses and guide therapeutic intervention.