The papers in this Volume were given at a two-day Conference on the subject of Optoelectronics in Medicine. The meeting was held in Florence, and promoted by the Consortium Centro di Eccellenza Optronica (C.E.O.). It represented the first of a series of Meetings on Optoelectronics that C.E.O. is organizing in order to stimulate new developments in this field and more efficient cooperation among local, national, and international research centers, industries, utilizers, etc .. Italian scientists have contributed consistently to the development of laser sources and to their applications to Medicine. A significant role has also been played by research institutes and industries in Florence. However, in this Conference, and in the Proceadings only a few Italian scientists were invited to present a lecture, thus offering the local and national communities as wide an international view as possible. Many more were present, however, as chairmen, and contributed successfully to making the discussions stimulating and fruitful. AB Editor, I had to substitute last-minute missing manuscripts with papers of my own, in order to keep the scheduled index of papers. The contributions presented at the Conference are written as extended, review­ like papers to provide a broad and representative coverage of the fields of light sources, optoelectronic systems for medical diagnosis, and light and laser applications to Medicine.