Book excerpt: This encyclopedia covers the definitions, concepts, methods, theories, and application of evidence-based pharmaceutical public health and health services research. It highlights why and how this field has a significant impact on healthcare. The work aims to synthesize baseline knowledge as well as the latest and cutting-edge research-based information. The encyclopedia collates information on public health, health services research, evidence-based pharmacy practice and its impacts on patients, decision-makers and consumers. This reference work discusses all aspects of policy and practice decisions on medicines use, access and pharmacy services by covering broad aspects related to pharmacy practice, public health and health services research. The aim is to develop high-quality content, which will be a must-read and be used as a reference source at all pharmacy and medical schools in the world. The health services research investigates the impact of social factors, organizational policies, financing systems, medical technologies and personal influence on access, quality and cost of healthcare concerning the quality of life of the patients. This reference work fundamentally promotes the evidence-based evaluation of healthcare services and thus will improve the better access and delivery of healthcare services. Also, pharmacy, medical and health services students and researchers need a broad understanding of pharmaceutical public health, evidence-based approaches to delivering care, changing professional and patient behavior and undertaking research in these areas. In general, there is a need to build research capacity and capability in the pharmacy profession. EDITOR-IN-CHIEF: Professor Zaheer-Ud-Din Babar, University of Huddersfield SECTION EDITORS: Filipa Alves da Costa, University of LisbonZubin Austin, University of TorontoDalia Dawood, National Institute for Health and Care Excellence Andy Gray, University of Kwa Zulu-NatalRachele Hendricks-Sturrup, Duke Margolis Center for Health PolicyJason Hsu, Taiwan Medical UniversityRabia Hussain, Universiti Sains MalaysiaChristine Y. Lu, Harvard Medical School and Harvard Pilgrim Health Care InstituteMohamed Izham Mohamed Ibrahim, Qatar UniversityPrasad Nishtala, University of BathDerek Charles Stewart, College of Pharmacy, Qatar University Fatima Suleman, University of Kwa Zulu-NatalZaheer-Ud-Din Babar, University of Huddersfield