A new first-of-its kind technique based on ultra-sound pulsed-Doppler velocimetry (UPDV) is proposed to measure flow velocities in stirred tanks as a non-intrusive manner for laminar and turbulent regimes of Newtonian and Non-Newtonian (complex mixture) fluids. Two ultra-sound probes at 1 and 2 MHz were tested and the salient features of these probes were analyzed. Measured velocity profiles in a stirred tank compared favorably with those obtained by microimpeller (intrusive) method and by laser Doppler velocimetry (LDV non-intrusive) technique. The presence of bubbles in the liquid phase greatly hampers the reliability of the UPDV technique, but when this constraint is removed or minimized, the technique remains adequate for rapid spatial mapping of flow velocity in pure liquid and emulsion systems.