Lyme disease, or Lyme borreliosis, is a zoonosis found throughout the Northern Hemisphere. It is by far the most common tick-borne infection in Europe. The incidence of the disease varies greatly from country to country, and even within a single country, depending on the region. Due to its geographical characteristics, and particularly because the Vosges Mountains cover a large part of its territory, Alsace is a region where Lyme disease is widespread. To date, there have been only partial and sporadic epidemiological studies on this disease in France, which do not allow for a precise determination of the disease’s incidence. This is why a regional working group comprising public health professionals and clinicians (Appendix 5) has developed a study protocol aimed at establishing surveillance of Lyme disease in Alsace, based on the reporting of new cases of the disease. The purpose of this brochure is to present the practical details of the surveillance program in which you will participate, as well as the clinical, biological, therapeutic, and ecological aspects of the disease. (R.A.)