BACKGROUND: Several reports indicate a high incidence of intensive care delirium. To develop strategies to prevent this complication, validated instruments are needed. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is widely used. A binary result diagnoses delirium. The Neelon and Champagne (NEECHAM) Confusion Scale recently has been validated for use in the ICU and has a numeric assessment. This scale allows the patients to be classified in four categories: non-delirious, at risk, confused, and delirious. In this study, we investigated the results of the NEECHAM scale in comparison with the CAM-ICU. METHODS: A consecutive sample of 172 non-intubated patients in a mixed ICU was assessed after a stay in the ICU for at least 24 hours. All adult patients with a Glasgow Coma Scale score of greater than 9 were included. A nurse researcher simultaneously assessed both scales once daily in the morning. A total of 599 paired observations were made. RESULTS: The CAM-ICU showed a 19.8% incidence of delirium. The NEECHAM scale detected incidence rates of 20.3% for delirious, 24.4% for confused, 29.7% for at risk, and 25.6% for normal patients. The majority of the positive CAM-ICU patients were detected by the NEECHAM scale. The sensitivity of the NEECHAM scale was 87% and the specificity was 95%. The positive predictive value and the negative predictive value were 79% and 97%, respectively. The diagnostic capability in cardiac surgery patients proved to be lower than in other patients. CONCLUSION: In non-intubated patients, the NEECHAM scale identified most cases of delirium which were detected by the CAM-ICU. Additional confused patients were identified in the categorical approach of the scale. The NEECHAM scale proved to be a valuable screening tool compared with the CAM-ICU in the early detection of intensive care delirium by nurses.