This volume contains the Proceedings of a two-week course on "Laser Applications to Biology and Medicine" held from September 4 to 16, 1983 in Erice, Italy. This is the 10th annual course of the International School of Quantum Electronics organized under the auspices of the "E. Majorana" Center for Scientific Culture. ,Among the possible approaches to a course on Laser Applications to Biology and Medicine, the one which emphasizes the scientific and technological aspects of the advanced laser techniques when applied to laboratory and clinical tests has been chosen. In fact, it reflects the new policy of the School to stress the advanced scien­ tific and technological achievements in the field of Quantum Elec­ tronics. Accordingly, the Course has given the broadest information on the ultimate performances already achieved and the perspectives of their applications. Because of the great variety of applications of laser in biology, medicine, chemistry, engineering and related branches of science, this school addressed a subject of interdisciplinary interest. The formal sessions have been balanced between tutorial presentations and lectures focusing on unsolved problems and future directions. In addition, wide time has been provided for the par­ ticipants to meet together informally for additional discussions on the forefront of current work. Therefore the character of the Course was a blend of current research and tutorial reviews.