Older patients are particularly vulnerable to harm during hospitalization, such as falls and adverse drug events. This review sought to examine the scale, types, causes, preventability, and outcomes of adverse events in elderly inpatients. Only nine relevant studies were identified and summarized in systematic searches. The studies had varying definitions of adverse events; for example, some did not include geriatric syndromes like delirium that may result as a complication of underlying illness rather than as a consequence of a health care process. The authors argue that the standard definition of adverse events affecting geriatric patients should include these syndromes, even if they are not felt to be preventable. This review demonstrates that a more comprehensive picture of adverse events in older patients is required.