Within the fields of public health, medicine, and pharmacy practice, innovative technologies, such as computer-based patient records, personal health information systems, and unified electronic claims systems, continue to broaden access to health information and health services delivery for at-risk and underserved populations in America (Levin & Hanson, 2000; Puskin & Kumekawa, 2001). This chapter will examine some of the major issues related to public health informatics. It will include a definition of public health informatics, a general discussion of the history of informatics technology, the types of information systems used in public health settings with emphasis on pharmacy applications, and emerging trends and innovations in public health informatics.