Peripheral arterial disease (PAD) is an underdiagnosed circulatory problem in the primary care setting. Individuals are at increased risk for cardiovascular disease; therefore, there is the need for a technique capable of early identification and detection of patients with PAD. The focus of this study was to compare the accuracy of a new operator-independent method of measuring ankle brachial index (ABI) with the traditional Doppler ultrasound method of determining ABI. In 246 limbs the authors compared ankle systolic pressures and ABI measured by a new automated oscillatory method called the ABIgram with those measured by standard Doppler ultrasound. In phase 1, the 2 methods for measuring ankle systolic pressure had a mean difference of 2 mm Hg with a standard deviation of 6.7 mm Hg. In phase 2 the mean difference was 3.1 mm Hg with a standard deviation of 5.1 mm Hg. Further, ABI as measured by the 2 methods fell within 1% and demonstrated a 5% error in reproducibility. These numbers pass the SP-10 standard for medical devices established by the FDA. The ABIgram module of the Vasocor Vascular Diagnostic Center offers primary care physicians the ability to rapidly obtain ABI measurements comparable to the standard technique. Further, the ABIgram may be operated by staff commonly found in the primary care setting.