The Emerging Diseases Epidemiology Unit was founded on July 1st, 2001. Its mandate was to develop its own research agenda in the field of infectious diseases epidemiology, and to provide expertise in epidemiology and biostatistics to other laboratories. Based on the potential for collaborations with the international network of Institut Pasteur, and on our past experience in international health, we decided to focus on the epidemiology of infectious and tropical diseases in resource-limited countries. Each researcher has its own field of expertise: Arnaud Fontanet in analytical epidemiology (cohort and case-control studies), Muriel Vray in the methodology of clinical trials, Michel Garenne in demography, Tamara Giles-Vernick in social sciences, and Romulus Breban in mathematical modeling. Main projects include hepatitis C in Egypt (see www.hepnile.org), children diarrhea in Central African Republic, Buruli ulcer in Cameroun, acute encephalitis in Vietnam, bacterial meningitis in Niger, and emerging viruses (MERS-CoV). Emphasis has been put in clinical research, i.e., cohort studies and clinical trials. In addition, four staff members, Yoann Madec, Loïc Chartier, Lénaïg Lefouler and Laura Tondeur provide transversal support to all projects of the unit in biostatistics and data management. We also offer expertise in the area of epidemiology and biostatistics to other research units of the institute and organize epidemiology and biostatistics courses for the Epidemiology and Public Health Pole of the Institut Pasteur Teaching Centre. These courses make the “infectious diseases risk” specialization of the Pasteur/CNAM School of Public Health.