Health Economics is an essential instrument for health management, and economic evaluations can be considered as tools assisting the decision-making process for the allocation of resources in health. Currently, economic evaluations are increasingly being used worldwide, thus encouraging evidence-based decision-making and seeking efficient and rational alternatives within the framework of health services activities. In this review, we present an overview and define the basic types of economic evaluations, with emphasis on complete Economic Evaluations (EE). In addition, we review key concepts regarding the perspectives from which EE can be conducted, the types of costs that can be considered, the time horizon, discounting, assessment of uncertainty and decision rules. Finally, we describe concepts about the extrapolation and spread of economic evaluations in health.