SummaryComprehensive geriatric assessment is an established clinical approach. It reduces mortality and improves the physical wellbeing of older people in the community or hospitalised for medical reasons. Pre-operative comprehensive geriatric assessment seems a plausible method for reducing adverse postoperative outcomes. The objectives of this systematic review and narrative synthesis are to describe how pre-operative comprehensive geriatric assessment has been used in surgical patients and to examine the impact of comprehensive geriatric assessment on postoperative outcomes in older patients undergoing scheduled surgery. We searched MEDLINE, EMBASE and Web of Science from 1980 to 2013 (week 26). We included five studies: two randomised controlled trials and three before-and-after intervention quasi-experimental studies. Patient populations, interventions and outcome measures varied between studies. Both the randomised trials showed benefit on postoperative outcomes, including medical complications. Two of the before-and-after studies reported a positive impact on postoperative length of stay and other outcomes. The heterogeneity of study methods, populations, interventions and outcomes precluded meta-analysis. Based on this narrative synthesis, pre-operative comprehensive geriatric assessment is likely to have a positive impact on postoperative outcomes in older patients undergoing elective surgery, but further definitive research is required. Clinical services providing pre-operative comprehensive geriatric assessment for older surgical patients should be considered. An increasing proportion of the ageing population is undergoing surgery [1]. Despite the benefits of surgery seen in this population, the rate of adverse postoperative outcomes increases with age [2]. Postoperative complications are predominantly medical rather than surgical [3], and their increased rate is associated with physiological age [4], multimorbidity [5,6] and geriatric syndromes, including frailty [7], sarcopenia [8] and delirium [9]. Although adverse postoperative outcomes and the risk factors for developing these are well described in older surgical patients [2], a national UK report has highlighted deficiencies in the care provided to this patient population [10]. Furthermore, pre-operative assessment has not been adapted to identify and modify these geriatric syndromes and multi-morbidity 8