Velocity measurements in major blood vessels were obtained in studies of volunteers using magnetic resonance imaging (MRI) and compared with Doppler ultrasound (US). The vessels studied were the abdominal aorta, superior mesenteric artery, common carotid artery, superficial femoral artery and middle cerebral artery. Using a paired t-test, no significant difference was found between velocity values estimated by MRI and US (p > 0.08). The relative advantages of each technique in radiological practice are discussed.