Metal ions and proteins are ubiquitous. Therefore, not surprisingly, new protein-metal interactions continue to be dis covered, and their importance is increasingly recognized in both physical and life sciences. Because the subject matter is so broad and affects so many disciplines, in organizing this Symposium, I sought participation of speakers with the broadest possible range of interests. Twenty-two accepted my invitation. To supplement the verbal presentations, the Proceedings include five closely re lated invited contributions. The ideas expressed are those of the various authors and are not necessarily approved or rejected by any agency of the United States Government. No official recommendation concerning the sub ject matter or products discussed is implied in this book. This book encompasses many aspects of this multifaceted field. Topics covered represent biochemical, immunochemical, bioorganic, biophysical, metabolic, nutritional, medical, physiological, toxi cological, environmental, textile, and analytical interests. The discoveries and developments in any of these areas inevitably illumine others. I feel that a main objective of this Symposium, bringing together scientists with widely varied experiences yet with common interests in protein-metal interactions, so that new understanding and new ideas would result has been realized. I hope that the reader enjoys and benefits from reading about the fascinat ing interactions of metal ions and proteins as much as I did.