Methods, just as diseases or scientists, have their own history. It is important for scientists to be aware of the genesis of the methods they use and of the context in which they were developed. A History of Epidemiologic Methods and Concepts is based on a collection of contributions which appeared in "SPM International Journal of Public Health", starting in January 2001. The contributions focus on the historical emergence of current epidemiological methods and their relative importance at different points in time, rather than on specific achievements of epidemiology in controlling plagues such as cholera, tuberculosis, malaria, typhoid fever, or lung cancer. The papers present the design of prospective and retrospective studies, and the concepts of bias, confounding, and interaction. The compilation of articles is complemented by an introduction and comments by Prof. Alfredo Morabia which puts them in the context of current epidemiological research.