Conventional methods used for measuring regional renal blood flow, such as laser Doppler flowmetry, are highly invasive and each measurement is restricted to a discrete location. The aim of this study was to determine if ultrasound imaging in conjunction with enhanced contrast agent (microbubbles; Vevo MicroMarker, VisualSonics) could provide a viable non-invasive alternative. This was achieved by determining changes in renal cortical and medullary rate of perfusion in response to a bolus injection of endothelin-1 (ET-1, 0.6, 1.0, or 2.0 nmol/kg) and comparing these responses to those observed in separate groups of mice with conventional laser Doppler methods. Intravenous infusion of ET-1 in anesthetized male C57bl/6 mice resulted in a dose-dependent increase in mean arterial pressure and a dose-dependent decrease in total renal blood flow as measured by pulse wave Doppler. ET-1 infusion resulted in a dose-dependent decrease in regional kidney perfusion as measured by both ultrasound with enhanced contrast agent and laser-Doppler measurements, verifying the use of ultrasound to measure regional kidney perfusion. Noted limitations of ultrasound imaging as compared to laser Doppler flowmetry included a lower degree of sensitivity to changes in tissue perfusion and the inability to assess rapid or transient changes in tissue perfusion. In conclusion, ultrasound represents an effective and non-invasive method for the measurement of relatively short-term, steady-state changes in regional blood flow in the mouse kidney.