This introductory course in epidemiology provides an analysis of the epidemiologic approach to problems of health and disease. The basis principles and methods of epidemiology are presented in three sections of this course. The sections are designed to provide the student with a basic understanding of epidemiologic methods and study design and the place of epidemiology in preventive and clinical medicine. This course is designed for students from a wide variety of backgrounds: health services, administrators, policymakers, practitioners, and clinicians.