This book deals with a new, developing subfield of nuclear physics. The large enhancement of parity violation effects in compound nuclear states, predicted by theory, has been observed in several laboratories. This has opened up new possibilities of studying parity (and possibly time reversal) violation. These investigations also provide new insights into the structure of the compound nucleus. Theoretical research of these phenomena is at its beginning. The book contains a state-of-the-art account of this subject and other aspects related to parity and time reversal violation.