The cost-effectiveness of the Intensive Care Unit after three decades of development has yet to be demonstrated. Accurate ICU resource allocation is limited by our inability to measure cost-effectiveness. Measurement tools have been developed and refined that will give a prediction of in-hospital mortality of groups of critically ill patients. However, these measures will not predict with certainty individual patient outcomes, and take no account of quality of life. Methodology to examine long-term outcome and quality of life after intensive care is still in its infancy. Measurement of ICU cost is limited by a lack of cost-accounting models that not only reflect true cost but that are clinically applicable.