Introduction:The ability of patients to finalise their affairs at the end of life is an often neglected aspect of quality of life (QOL) measurement in palliative care effectiveness research despite compelling evidence of the high value patients place on this domain. Objective: This paper describes the preliminary development and evaluation of a new, single-item, end-of-life patientreported outcome measure (EOLPRO) designed to capture changes in the ability of patients to finalise their affairs at the end of life. Methods: Cognitive interviews with purposively sampled Australian palliative care patients (N = 9) were analysed thematically to explore content validity. Simultaneously, secondary analysis of data from a randomised controlled trial comparing ketamine and placebo for the management of cancer pain (N = 185) evaluated: construct validity; test-retest reliability; and responsiveness. Results:Preliminary findings suggest patients interpret the new measure consistently. The EOLPRO captures the ability to complete physical tasks and finalise practical matters although it is unclear whether emotional tasks or resolution of relationship issues are considered. Personal and financial affairs should be separated to allow for differences in ability for these two types of affairs. The significant correlation between performance status and EOLPRO scores (r = 0.41, p,<.01, n = 137) and expected relationships between EOLPRO and proximity to death and constipation demonstrated construct validity. Pre-and post-treatment EOLPRO scores moderately agreed (n = 14, k = 0.52 [95% CI 0.19, 0.84]) supporting reliability. The measure's apparent lack of sensitivity to discriminate between treatment responders and non-responders may be confounded. Conclusion:Based on the preliminary findings, the EOLPRO should be separated into 'personal' and 'financial' affairs with further testing suggested, particularly to verify coverage and responsiveness. Initial evaluation suggests that the single-item EOLPRO is a useful addition to QOL outcome measurement in palliative care effectiveness research because common palliative care specific QOL questionnaires do not include or explicitly capture this domain.