This volume contains the proceedings of the 16th American Peptide Symposium, held June 26-July 1, 1999, at the Minneapolis Convention Center in Minneapolis, Minnesota. This biennial meeting was held under the auspices of the American Peptide Society. The fortunate coincidence of the calendar allowed the theme of the meeting to be set as Peptides for the New Millennium. The approximately 1200 participants who converged in the Twin Cities from academic and industrial institutions in 36 countries were treated to a conference that left almost everyone with an enthusiastic vision for the future of the field. A total of 116 contributions were selected for oral presentation (38 in plenary sessions and the remainder in dual sessions). A further 12 talks were given by graduate students and postdoctoral fellows at the Young Investigators' MiniSymposium. Essentially all of the lectures are included in these Proceedings.