A review is given of quantitative techniques and clinical applications of arterial Doppler ultrasound. The currently available Doppler equipment of stand-alone continuous wave and pulsed wave units, duplex systems and colour flow systems is briefly described. Doppler ultrasound can be divided into procedures concerned with waveform analysis, volume flow measurement and more recently colour flow imaging. Arterial Doppler waveform analysis is considered for a number of areas including carotid, lower limb, renal and renal transplant, obstetrics, adult cerebral, neonatal cerebral, and tumour studies. Using a duplex scanner volume flow in arteries can be measured from estimates of vessel cross sectional area, mean Doppler frequency and beam-vessel angle. The errors associated with each of these measurements is discussed, and reports of experimentally determined in vivo accuracy of volume flow measurements made using this technique are considered. Other volume flow measurement techniques including the promising attenuation compensation method are also explored.