Economic analyses of prevention and treatment interventions in rheumatology are potentially powerful tools for evaluating many complex decisions facing clinical and public policy makers. Cost-effectiveness, cost-utility, and cost-benefit analyses allow for the assessment of the trade-offs between expended resources and expected health benefits. This review describes 12 cost-effectiveness analyses done in the past year. Each relates to a different intervention for a variety of rheumatologic conditions including osteoporosis, rheumatoid arthritis, the use of cyclooxygenase-II inhibitors, infected total joint replacements, back pain, and Lyme disease. While cost-effectiveness analyses of the use of the new biologic agents in rheumatoid arthritis have been presented at national meetings, these have yet to be published. Proper use of cost-effectiveness analysis could provide valuable evidence about treatment decisions for clinical and public policy makers in rheumatology.