Pharmacoeconomic methods have become influential in healthcare resource allocation decision-making through the implementation of health technology assessment (HTA). Many countries have adopted HTA at the national level, supported by public agencies. The widespread adoption of HTA across different contexts has resulted in a variety of structures and processes designed to suit alternative cultural, political and resource environments. This international experience provides a wealth of insight for countries looking to develop the role of HTA in their setting, with some general lessons for effective policymaking. In this chapter, we provide an overview of the development of HTA around the world and explore some of the factors that determine the role and influence of pharmacoeconomics in drug reimbursement policy. It is important that HTA and technology appraisal processes should not be subject to political control. Agencies should provide clear methodological guidance and outline transparent procedures to support fair and consistent decision-making. In resource-constrained settings, it is important to build capacity and human resource to support HTA.