This piece describes how pharmacoeconomic studies promote rational and efficient drug use. The pharmaceutical industry of Cuba has become more interested in such analytical techniques and has begun to use them to develop strategies for research and development, production, and product marketing. This paper describes research related to pharmacological treatments, through practical examples of pharmacoeconomic evaluations carried out jointly by the pharmaceutical sector and the health care system in Cuba. These efforts demonstrate the applicability that pharmacoeconomics has for health decision-making based on clinical effectiveness and the costs of the pharmacotherapeutics used.