This textbook provides an excellent introduction to a new and rapidly developing field of research. The topics treated include a detailed exploration of the quantum aspects of nonlinear dynamics, quantum criteria to distinguish regular and irregular motion, antiunitary symmetries (generalized time reversal) and a thorough account of the quantum mechanics of dissipative systems. Each chapter is accompanied by a selection of problems which will help the student to test and deepen his/her understanding and to acquire an active command of the methods. The second edition is significantly expanded. Of the considerable theoretical progress lately achieved, the book focusses on the deeper statistical exploitation of level dynamics, improved control of semiclassical periodic-orbit expansions, and superanalytic techniques for dealing with various types of random matrices.