IX The International Seminar on the Immunological System as a Target for Toxic Damage was held at The Commission of the European Communities (CEC) in Luxembourg on 6-9 November 1984. It was organized by the CEC and the International Programme on Chemical Safety of UNEP/ILO/WHO with the support of the u. S. Environmental Protection Agency and the National Institute of Environmental Health Sciences - USA and with the participation of the International Society of Immunophar macology. These bodies are actively concerned with the scientific and applied aspects of immunotoxicology. The Seminar consisted of thirty-four invited papers and three major panel discussions covering current and future test strategies for the screening of immunotoxic substances, hypersensitivity and the health implications of immunotoxico logical problems. It was attended by more than 200 scien tists from 27 countries representing all the Member states of the European Economic Community and the six Regions of the World Health Organization. These scientists represented many different disciplines and interests. The Seminar’s principal objectives were: a review of recent advances in knowledge concerning the structure, function and dysfunction of the immunological system; - a review of the effects of xenobiotics on the immune system in animals and humans; an examination of the human health implications of immunotoxicity; discussion and critical analysis of the procedures for the assessment of immunological damage, a discussion of needs for the further development of laboratory and epidemiological methods and their validation, and a consideration of current test strategies.