Population ageing is associated with an increase in hospital admissions. Defining the factors that affect the risk of hospital readmission could identify individuals at high risk and enable targeted interventions to be designed. This aim of this study was to identify the risk factors for hospital readmission in elderly people. A systematic review of the literature published in English or Spanish was performed by electronically searching EMBASE, MEDLINE, CINAHL, SCI and SSCI. Some keywords were aged, elder, readmission, risk, etc. Selection criteria were: prospective cohort studies with suitable statistical analysis such as logistic regression, that explored the relationship between the risk of readmission with clinical, socio-demographic or other factors in elderly patients (aged at least 75 years) admitted to hospital. Studies that fulfilled these criteria were reviewed and data were extracted by two reviewers. We assessed the methodological quality of the studies and prepared a narrative synthesis. We included 12 studies: 11 were selected from 1392 articles identified from the electronic search and one additional reference was selected by manual review. Socio-demographic factors were only explanatory in a few models, while prior admissions and duration of hospital stay were frequently relevant factors in others. Morbidity and functional disability were the most common risk factors. The results demonstrate the need for increased vigilance of elderly patients who are admitted to hospital with specific characteristics that include previous hospital admissions, duration of hospital stay, morbidity and functional disability.