OBJECTIVE To identify scales that can establish a quantitative assessment of delirium symptoms in critically ill patients through a systematic review. METHODS Studies that evaluated delirium stratification scales in patients hospitalized in intensive care units were selected in a search performed in the MedLine database. Validation studies of these scales and their target patient populations were analyzed, and we identified the examiner and the signs and symptoms evaluated. In addition, the duration of the application and the sensitivity and specificity of each scale were assessed. RESULTS Six scales were identified: the Delirium Detection Score, the Cognitive Test of Delirium, the Memorial Delirium Assessment Scale, the Intensive Care Delirium Screening Checklist, The Neelon and Champagne Confusion Scale and the Delirium Rating Scale-Revised-98. CONCLUSION The scales identified allow the stratification and monitoring of critically ill patients with delirium. Among the six scales, the most studied and best suited for use in the intensive care units was the Intensive Care Delirium Screening.