This book is a summary of the presentations and discussions at the Workshop on Methods of Pesticide Exposure Assessment held in Ottawa, Canada, on October 5-8, 1993. The event was a joint effort of Health Canada and the North Atlantic Treaty Organisation and was officially supported by the United States Environmental Agency and the Organisation for Economic Co-operation and Development (OECD). The goal of the workshop was to examine current issues in the field of pesticide exposure assessment with the aim of reaching an internationally harmonized approach to methods of exposure assessment. With regulatory agencies of OECD Member countries moving towards the harmonization of data requirements, it was timely and beneficial to bring together international experts in the field of pesticide exposure assessment to discuss current issues. Approximately 60 delegates and 20 observers participated, including individuals from 15 different countries representing academia, government, industry and international organizations. A guidance document on methods of pesticide exposure assessment was presented as a means to achieving the goal of international for critique and discussion harmonization. After extensive discussion, the workshop delegates agreed in principle to procedures for revising the guidance document. Following revision and further review by a designated peer review group, the revised document will be submitted to the OECD for consideration as a draft OECD Guidance Document on pesticide exposure assessment methods. Both the revised and original documents are included in these proceedings.