Delirium frequently occurs among hospital in-patients, with significant attributable healthcare costs. It is associated with long-term adverse outcomes, including an eightfold increased risk of subsequent dementia. The purpose of this article is to inform clinicians of the best practices for spotting, stopping and treating delirium and provide guidance on common challenging clinical dilemmas. For spotting delirium, suggested screening tools are the 4 ‘A's Test (in general medical settings) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Prevention is best achieved with multicomponent interventions and targeted strategies focusing on: (a) avoiding iatrogenic causes; (b) brain optimisation by ensuring smooth bodily functioning; (c) maintaining social interactions and normality. Non-pharmacological approaches are the first line for treatment; they largely mirror prevention strategies, but the focus of empirical evidence is on prevention. Although sufficient evidence is lacking for most pharmacological approaches, an antipsychotic at low doses for short durations may be of utility for highly distressing or high-risk situations, particularly in hyperactive delirium, but only as a last resort.