Many of the drugs prescribed commonly to palliative care patients have potentially significant side-effects and are of unproven benefit. The acquisition of evidence to support the prescribing of these drugs has been very slow. Single patient trials (SPTs) (also known as n-of-1 trials) offer a potential means of obtaining the evidence necessary to support or refute the use of several of the drugs and interventions whose use is currently based on physician experience or anecdote alone. A list of SPTs considered "most urgent", for commonly employed treatments and for the most common and most troublesome symptoms in palliative care is presented. These are drugs for which the gap between evidence and practice is greatest, where the evidence of efficacy is most lacking, where significant side effects potentially lead to the greatest morbidity, or where cost is a major patient burden. Although not all the drugs used in palliative care are suitable, SPTs provide a potential alternative method of gathering evidence in palliative care.