This volume contains the proceedings of the Second International Peptide Symposium and the Seventeenth American Peptide Symposium, held on 9-14 June, 2001, at the Town and Country Resort in San Diego, California. The biennial meeting was held under the auspices of the American Peptide Society. In addition to the main Symposium, we were honored to have the Merrifield Satellite Symposium, honoring Bruce Merrifield's accomplishments on his 80th birthday.Over 1250 participants from around the world attended the lectures, posters, and exhibits. Reflecting the international nature of the Symposium, there were participants from 37 countries in attendance. In addition to the 75 plenary lectures, there were over 575 poster presentations, and 70 commercial exhibits as well as booths from the American, Australian, Chinese, European, and Japanese Peptide Societies.These proceedings include plenary lectures and oral and poster presentations collected from a wide diversity of topics providing a truly comprehensive and up-to-date overview of the field of peptide science. This publication contains essential reference information for researchers active in peptide science.