The 2nd International Congress on Deuterium Depletion was held on 17-18 May 2012 in Budapest, Hungary (www.deuteriumdepletion.com), as a follow-up to the 1st International Symposium on Deuterium Depletion held in Budapest in the spring of 2010. The goal of the organizers was to provide a global and comprehensive update of the newest results and developments in the research of deuterium depletion, and to give the researchers and medical practitioners a new opportunity to get acquainted with this expanding field of science, share their results and experience. Researchers and practitioners from several countries (Hungary, USA, France, Romania, Russia and China) presented 16 lectures on the various biological effects of deuterium depletion in the field of cancer research, diabetes research and anti-aging science.