Color Doppler ultrasonography was used to determine time-average mean velocity and cross-sectional area of the common iliac artery in bullfrogs (Rana catesbeiana) and marine toads (Bufo marinus). Volumetric blood flow and weight-adjusted blood flow measurements were calculated from this data. Volumetric flow rates of frogs (31.8 ml/min) and toads (23.6 ml/min) did not differ statistically. However, when flow rates were adjusted for body mass, toads displayed a significantly greater flow rate of 238.1 ml/min/kg compared to 114.4 ml/min/kg for frogs.