Recent clinical publications have increasingly emphasized comparison of cost with benefits in such areas such as drug therapies, surgical procedures, and prophylaxis regimes within certain populations. In the past, cost analysis was based principally on the comparative market price of new treatment compared with standard therapy. Benefits were assessed solely in terms of objective clinical and imaging improvement. Now, issues such as quality of life, early return to occupation, and subjective symptoms of pain and discomfort caused by a treatment are also being critically evaluated. Addressing these latter issues, however, is often complicated and expensive. This article reviews some terms and principles of cost analysis, cost effectiveness, and cost-benefit analysis. Examples are given of recent attempts to quantify costs and benefits for individuals, hospitals, health organizations, and society as a whole. Guidelines are suggested concerning how these studies can be applied to oral and maxillofacial surgery.