It is nearly a decade since the first Male Mediated Developmental Toxicity conference was held in Pittsburgh. The continuing public/scientific interest, growing amounts of animal data, introduction of invative techlogies, and increasing quantity of human epidemiological studies all suggest that male-mediated developmental toxicity is of major concern. A number of researchers concluded that a Second International Confer- ence on Male Mediated Developmental Toxicity was necessary. The ensuing volume is particularly timely because it impacts on areas of special emphasis in many countries, with respect to children's and reproductive health, as well as to basic molecular mecha- nisms of environmental insult, and genetic susceptibility and predisposition. The Programme and Local Organizing Committee, composed of Barbara Hales (Chair, McGill University), BernardRobaire (McGill University), Daniel G. Cyr (INRS/ Armand Frappier), Jacquetta M. Trasler (McGill University), Andrew F. Olshan (Uni- versity of North Carolina), Sally Perreault Damey (US EPA), Donald R. Mattison (March of Dimes), and Jan M. Friedman (University of British Columbia), spent over two years identifying individuals who had made key contributions in this field over the past decade and planning various aspects of the meeting. The meeting was held in Montreal in June 2001. A total of 132 persons, coming from five continents and representing some 18countries, took an active role in the proceedings. The conference was considered by all attendees to be a rousing success. Important discussions were held in the four break-out sessions, with a preliminary set of recommendations for action being presented by each panel.