This document, authored by the Doppler Quantification Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography, provides recommendations for the accurate recording and measurement of Doppler data in echocardiography. The introduction highlights the importance of Doppler echocardiography as a noninvasive technique for assessing hemodynamic parameters, emphasizing the need for meticulous technique and understanding of Doppler principles and flow dynamics. The document outlines the general principles of Doppler technology, including the Doppler equation and the three modalities of Doppler echocardiography: pulsed wave (PW) Doppler, continuous wave (CW) Doppler, and color Doppler imaging. It explains how these modalities are used to measure blood flow velocity and pressure gradients, with specific applications in evaluating cardiac function, valvular disorders, and diastolic function. Key recommendations are provided for recording and measurement techniques, emphasizing the importance of maintaining parallel orientation between the sound waves and blood flow to minimize errors in velocity measurements. Detailed guidelines are given for using PW and CW Doppler, color Doppler, and tissue Doppler to measure flow velocity, stroke volume, and cardiac output. The document also discusses the application of Doppler in assessing diastolic function, estimating right-sided pressures, and evaluating prosthetic valves. The document concludes by emphasizing the dynamic nature of echocardiography and the need for ongoing training and experience to maintain expertise in Doppler echocardiography.This document, authored by the Doppler Quantification Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography, provides recommendations for the accurate recording and measurement of Doppler data in echocardiography. The introduction highlights the importance of Doppler echocardiography as a noninvasive technique for assessing hemodynamic parameters, emphasizing the need for meticulous technique and understanding of Doppler principles and flow dynamics. The document outlines the general principles of Doppler technology, including the Doppler equation and the three modalities of Doppler echocardiography: pulsed wave (PW) Doppler, continuous wave (CW) Doppler, and color Doppler imaging. It explains how these modalities are used to measure blood flow velocity and pressure gradients, with specific applications in evaluating cardiac function, valvular disorders, and diastolic function. Key recommendations are provided for recording and measurement techniques, emphasizing the importance of maintaining parallel orientation between the sound waves and blood flow to minimize errors in velocity measurements. Detailed guidelines are given for using PW and CW Doppler, color Doppler, and tissue Doppler to measure flow velocity, stroke volume, and cardiac output. The document also discusses the application of Doppler in assessing diastolic function, estimating right-sided pressures, and evaluating prosthetic valves. The document concludes by emphasizing the dynamic nature of echocardiography and the need for ongoing training and experience to maintain expertise in Doppler echocardiography.