Terms used to describe a patient's mental state, such as "confused", are often considered to be ambiguous and the meaning personal to individuals describing what they observe. Cognitive deficits are often subtle in their presentation and can easily be overlooked in the arena of acute nursing, with its focus on physical status. Clinicians are reported as not adequately assessing cognitive status and yet such deficits may impact on a patient's activities of living at all levels. Identification of alternations in a patient's mental status is important in maintaining patient safety and dignity. This article aims to review bedside assessment of a patient's mental status and the implications for nursing practice.