Using a retrospective analysis of the Intensive Care National Audit and Research Centre Case Mix Programme Database (ICNARC CMPD), we have summarised the characteristics and outcomes for mechanically ventilated patients admitted to UK intensive care units (ICUs) after cardiac arrest. Descriptive statistics on case mix, physiology, treatment, service delivery, outcome and activity were described separately for community cardiac arrest, in-hospital cardiac arrest (peri-operative) and in-hospital cardiac arrest (not peri-operative). The impact on outcome of several patient characteristics and physiological values were analysed using multivariable logistic regression. Mechanically ventilated survivors of cardiac arrest accounted for 24,132 (5.8%) of all admissions to the 174 ICUs in the ICNARC CMP. Of these, 10,347 (42.9%) survived to leave the ICU and 6778 (28.6%) survived to acute hospital discharge. The ICNARC model gives much better discrimination than APACHE II for predicting hospital mortality after admission to ICU following cardiac arrest: the predicted hospital mortality based on the APACHE II and ICNARC model was 41.9% and 79.7%, respectively.