ICU delirium is a common medical problem occurring in patients admitted to the intensive care units (ICUs). Studies have shown that ICU delirium is associated with increased mortality, prolonged hospitalization, prolonged mechanical ventilation, costs and the occurrence of cognitive disoders after discharge from ICU. The tools available for ICU delirium screening and diagnosis are validated tests available for all members if the medical team (physicians, nurses, physiotherapists). Their use for routine patient assessment is recommended by international medical and scientific societies. They have been implemented as Pain, Agitation, Delirium (PAD) Guidelines by the Society of Critical Care Medicine. Apart from monitoring, a strategy of prevention and treatment is recommended, based on non-pharmacological approach (restoration of senses, early mobilization, physiotherapy, improvement in sleep hygiene and family involvement) as well as pharmacological treatment (typical and atypical antipsychotics and dexmedetomidine). In this article, we present the risk factors of ICU delirium, available tools for monitoring, as well as options for prevention and treatment of delirium that can be used to improve care over critically ill patients.