The rise in healthcare expenditures due to the incorporation of new diagnostic and therapeutic technologies and increasing life expectancy is a major concern, particularly in developing countries. The role of economic evaluation in health is to optimize the benefits of available resources. This article aims to allow readers to identify the basic characteristics and types of economic evaluation in health and understand its methods, with an emphasis on infectious diseases. We thus review the following concepts: study perspective, analytic scope, costs, and discount rate. We also focus on characteristics of cost-minimization, cost-effectiveness, cost-utility, and cost-benefit analyses, with examples. The article describes the most popular study designs for economic evaluation, discusses different models, and examines the importance of sensitivity analysis. Our final comments address the importance of adopting economic evaluations in health in Brazil.