Pulse oximetry is a valuable, non-invasive method used for estimating oxyhaemoglobin saturation. It can give a bedside indication of the oxygenation and thus provide a valuable insight into the cause of breathlessness. Its use can help palliative care teams to determine the need to prescribe or to withhold oxygen therapy. The technology is well established and relatively inexpensive. Factors that influence readings include low perfusion states at the end of life. With a thorough understanding of its uses and limitations, pulse oximetry can assist multidisciplinary teams in providing better care to ill patients in the palliative care setting.