BACKGROUND: Case management is a collaborative practice involving coordination of care by a range of health professionals, both within the community and at the interface of primary and secondary care. It has been promoted as a way of reducing unplanned admissions in older people. OBJECTIVE: The objective was to systematically review evidence from randomized controlled trials regarding the effectiveness of case management in reducing the risk of unplanned hospital admissions in older people. METHODS: Eighteen databases were searched from inception to June 2010. Relevant websites were searched with key words and reference lists of included studies checked. A risk-of-bias tool was used to assess included studies and data extraction performed using customized tables. The primary outcome of interest was enumeration of unplanned hospital admission or readmissions. RESULTS: Eleven trials of case management in the older population were included. Risk of bias was generally low. Six were trials of hospital-initiated case management. Three were suitable for meta-analysis, of which two showed a reduction in unplanned admissions. Overall, there was no statistically significant reduction in unplanned admissions [relative rate: 0.71 (95% confidence interval, CI: 0.49 to 1.03)]. Three trials reported reduced length of stay. Five trials were of community-initiated case management. None showed a reduction in unplanned admissions. Three were suitable for meta-analysis [mean difference in unplanned admissions: 0.05 (95% CI: -0.04 to 0.15)]. CONCLUSIONS: The identified trials included a range of case management interventions. Nine of the 11 trials showed no reduction of unplanned hospital admissions with case management compared with the same with usual care.