The majority of hospital in-patients are older people, and many of these are at increased risk of readmission, which can be an adverse outcome for the patient. Currently there is poor understanding as to how best to reduce the risk of readmission. We searched MEDLINE, EMBASE and the Cochrane library for high quality review articles about readmissions. Each review was quality assessed by two reviewers. Grouped data and evidence from original papers is cited with 95% confidence intervals when possible. Nine review studies of sufficient quality were included. Two addressed risk factors for readmission, which included: age, poor functional status prior to admission, length of stay during the index admission, depression, cognitive impairment, malnutrition, social support and social networks/support. The seven other reviews addressed interventions to reduce readmission, which included: discharge planning, post-discharge support, post-discharge case management, and nutritional supplementation. It is possible to identify older people at risk of readmission using well-established risk factors; discharge planning, post-discharge support and nutritional interventions appear to be effective in reducing readmission. Combined interventions appear to be more effective than isolated interventions.