BACKGROUND Frailty is a geriatric syndrome characterized by the clinical presentation of identifiable physical alterations and decreased physiological reserve. The assessment of frailty syndrome has been recently related with post-surgical outcomes and overall mortality in older individuals. DESIGN AND DATA SOURCES We performed searches in Pubmed, Embase, Scopus, SCIELO and IME (Spanish medical index) databases from their start dates to February 2014 for original papers about the identification of the relationship between frailty and pre-operative risk evaluation in people aged 65 and over. REVIEW METHODS We followed criteria of systematic PRISMA guidelines. Two independent reviewers extracted descriptive information on frailty criteria and outcomes from the selected papers: of the 77 articles retrieved from the searches, 32 met the study inclusion criteria. RESULTS Severity of frailty syndrome significantly correlated with post-surgical mortality rates and with many although not all post-surgical complications. These relationships emerge in different type of surgical procedures and patients' features. The comparison of diagnostic tools to assess frailty in pre-operative risk evaluation are very few and to date, no recommendation can be made about the best scale to measure it. CONCLUSION Assessment of frailty syndrome should be added in the pre-operative risk assessment in older individuals.