Health expenditures and medication usage have increased dramatically in last years, situation that alerts governments and health authorities, and than can be related with some facts: not standardized medical prescription, excessive gains of the pharmaceutical industry, recent advances in biotechnology related with resource wastefulness, lack of communication between public health entities and clinical physicians and lack of consistent regulatory policies about drug prices. The importance of pharmacoeconomics is based on some aspects: better medical prescription, important role in commercialization and distribution of medicines, capacity of showing a broad and complete scenario of the social and economic impact of diseases, as opening research perspectives in different scientific fields. Within pharmacoeconomical analyses we can found those that show incomes (costs) in monetary units and show outcomes in monetary, natural or utility units: cost minimization, cost benefit, cost utility and cost effectiveness, and also we can found those analyses that study the general panorama of diseases (cost of illness studies). Health costs can be divided into: direct costs (medical and not medical), indirect (economical impact on society) and intangible (related with quality of life of patients and their families). Pharmacoeconomics can lead to a better medical practice, to more efficient health systems and to a more rational usage of resources. These studies are necessary for a proper structure of health programs, as for decision making. The inclusion of health economics concepts within medical and health sciences curricula is also recommended. © 2011 Asociación Colombiana de Reumatología