Since the publication of the first edition of this book six years ago both re search and applications in laser medicine have undergone substantial growth. The demand for novel techniques based on minimally invasive surgery has increased tremendously, and there is no end to it yet. Therefore, as the first edition ran out of stock, the publisher has asked me to prepare a second edition taking all these new developments into account. Well, here it is. Although minor changes and corrections have been made throughout the book, major changes have been limited to Chap. 4. The reason is that the theory presented in Chaps. 2 and 3 is basically complete and does not need any further modifications, except that the discussion on laser induced interstitial thermotherapy (LITT) in Sect. 3.2 has been extended by the technique of a multi-fiber treatment. On the other hand, the contents of Chap. 4 - the chapter on applications - strongly depend on the current state of the art. The second edition of this book covers all applications addressed in the first edition plus novel techniques for refractive corneal surgery and the treatment of caries. The success in refractive corneal surgery has significantly increased since the introduction of laser in situ keratomileusis (LASIK) described in Sect. 4.1.