Background: The accuracy and reliability of non-invasive oximetry for haemoglobin measurements were reported in operating rooms and intensive care units, though few studies evaluated this technology in emergency departments. The purpose of this study was to evaluate the accuracy and reliability of non-invasive SpHb readings from a portable device, in emergency department patients, compared to synchronous LabHb measurements. The authors sought to minimise external variables that could influence device performance, including learning curves and patient conditions, thus performed measurements by one trained user on stable adults only.