Doppler ultrasound is frequently used as a screening tool when assessing patients for arterial disease. The use of Doppler ultrasound to calculate the ankle brachial pressure index (ABPI) has been tested for reliability and reproducibility and has been found to be an accurate technique when used regularly by appropriately trained practitioners. An alternative to Doppler has been suggested using pulse oximetry to calculate the Lanarkshire Oximetry Index (LOI), which has been described as a feasible alternative to ABPI. This article compares the techniques and discusses the implications for practice.