Conference commemorating the centenary of the birth of prof. Jan Kostrzewski was held on 14^th. June 2016 at the National Institute of Public Health-NIH. Prof. Kostrzewski was an outstanding epidemiologist, founder of the Department of Epidemiology at the National Institute of Hygiene, Minister of Health and Chief Sanitary Inspector, Vice President of the World Health Assembly and the Chairman of the Executive Board of WHO. The conference was attended by family, former students and colleagues of prof. Kostrzewski. The conference commemorated not only extremely varied activities and professional achievements of Professor Kostrzewski in Poland and on international forums, but also him as a human being.