The use of Multifrequency Doppler spectral analysis (MFDSA) combined with ultrafast acquisition times was investigated for wall shear stress measurement in renal arteries. MFDSA relies on the use of the inherent additional frequencies present in a finite ultrasound pulse to provide additional analysis. The development of arterial disease in the renal arteries is of clinical interest as it is associated with increased risk of a number of life threatening conditions. A potential biomechanical marker of this damage is wall shear stress (WSS), which is linked to arterial wall stiffening as well as the formation of atherosclerotic plaques. A key requirement in the assessment of WSS is the accurate mapping of blood velocity close to the arterial wall. Therefore, it is of paramount importance that any technique measuring WSS has a high signal-to-noise ratio (SNR) as well as excellent velocity resolution. MFDSA combined with ultrafast acquisition times has the potential to improve the SNR and velocity resolution for the quantification of blood velocity. A series of anatomically realistic walled arterial flow phantoms (0–50% stenosis) were constructed with a range of wall stiffness values corresponding to different stages of arterial disease. These phantoms were employed for investigating the use of an Aixplorer (Supersonic-Imagine) ultrasound scanner for the measurement of velocity profiles. Inphase and Quadrature (IQ) data was acquired for a range of flow velocities (5–50 cm/s) and processed using custom code (Matlab) to determine the velocity data using Fourier analysis and MFDSA. The preliminary results indicate an average improvement in SNR of up to 27% when using MFDSA compared to standard Fourier analysis. Additional testing to improve the SNR and velocity resolution is planned. MFDSA combined with ultrafast imaging was found to demonstrate a marked improvement to the quality of blood velocity data which will ultimately improve the assessment of WSS.