Goal: To describe the case mix and severity of illness of Dutch ICU patients and outcome of treatment as expressed by the standardized mortality ratio (SMR). Methods: At the time of the analysis 61 ICUs were participating in the Dutch National Intensive Care Evaluation (NICE) registry. Reasons for admission, baseline characteristics, severity of illness on admission (APACHE II and SAPS II), chronic health conditions, comorbidities and outcome were collected in a prospective fashion. Results: In 2006 and 2007, a total of 91 179 patients were included in the NICE registry. These patients had a mean age of 63 years (SD 23 years), while most patients (28%) were between 70-80 years-old. Sixty percent of the patients were male, 23.6% had serious comorbid conditions (immunocompromised, respiratory or cardiovascular insufficiency, proven cirrhosis, haematological malignancy, AIDS, metastasized carcinoma, chronic kidney failure), 22 % were admitted after planned cardiopulmonary surgery, but most (53%) were admitted for emergency reasons. The overall (n=91 179) mean in-hospital mortality was 16.3%. Of these 91 179 patients 52 034 fulfilled the entry criteria for either the APACHE II or the SAPS II prognostic scoring system. The mean APACHE II score (n=53 962) was 16.4 with a standard variation of 8.4 points and a predicted rate of death of 25.8%. The mean SAPS II score (n=59 765) was 34.6 ± 19.4 (SD), while the predicted death rate was 24.1%. The standardized mortality ratio (SMR) based upon APACHE II of these patients was 0.73 with a 95% CI of 0.71 to 0.74. The SMR based upon SAPS II included patients (n=59 765) was 0.82 with 95% CI of 0.81 to 0.84. There was quite some variation between the referring specialties in SMR (ranging from 0.42-1.07 based upon SAPS II). Conclusion: This article provides an overview of case mix and outcome of Dutch Intensive Care Medicine and the deviation of case mix and outcomes between ICUs. As more than 60% of the Dutch ICUs have joined the NICE registry, the presented data provide valuable information on the application of Intensive Care Medicine in the Netherlands. Copyright © 2009, Nederlandse Vereniging voor Intensive Care. All rights reserved.