Delirium is a significant psychiatric disorder in intensive care units that has negative impact on morbidity and mortality of intensive care patients. Subjective clinical assessment of patients by non-psychiatric health professionals in intensive care units is not sufficient for detection and measurement of delirium. Therefore, different scoring scales for delirium assessment have been developed. This paper reviews the characteristics of commonly used scoring scales for assessment of delirium in intensive care units: the Confusion Assessment Method-Intensive Care Unit (CAM-ICU), the Intensive Care Delirium Screening Checklist (ICD-SC), the Nursing Delirium Screening Scale (Nu-DESC) and the Detecting Delirium Scale (DDS). Routine implementation of objective scoring scales is not widespread. Evidence suggests that objective assessment of delirium contributes to its early detection in intensive care and initiation of appropriate treatment. It is therefore advisable to make additional educational effort to provide an objective scoring scale for the assessment of delirium, such as CAM-ICU, to be routinely used in intensive care units.