Critical care providers are under increasing pressure to be attentive to cost concerns. The ICU consumes a significant amount of resources and, as such, is a frequently identified target of efforts to limit escalating healthcare costs. Attempts to reduce costs need not progress in a haphazard fashion. Rather, they can proceed in a logical, systematic manner with the assistance of formal economic studies. Cost-effectiveness analysis is one tool for these projects-it allows physicians to compare the financial consequences of different approaches to resource allocation. ICU physicians, therefore, must become familiar with the basic concepts that underlie cost-effectiveness analysis. Cost-effectiveness analyses that address many different aspects of critical care delivery are now commonly found in the critical care literature. With a framework for evaluating these studies, clinicians can better apply their findings to their own institutions.