There have been two major review articles on the iodine laser in the last ll seven years, liThe Photochemical Iodine Laser by K. Hohla and K. Kompa (Handbook of Chemical Lasers, edited by R. Gross and J. Bott, Wi 1 ey, New York,1976) and a SANDIA report (No. 78-1071, 1978) entitled liThe Atomic Iodine Laserll. Since then, a large body of new material has been published, and practical experience has been gained with large iodine laser systems in Garchi ng (ASTERIX II I) and in the USSR. These 1 asers have now become very reliable tools, especially in fusion-oriented plasma experiments, which represent their main field of application. They can deliver powers in excess of many terawatts per beam and are thus also suited for use in other areas such as X-ray lasers, incoherent X-ray sources, compression of matter and its behaviour at very high densities. The physics of the iodine laser is now rather well understood, and its technology has reached a standard adequate for the construction of large- scale systems in the multi-hundred kJ range. In view of this new situation, we thought it useful to document the present state of the art ina book. Its contents and the literature cited therein have been chosen to cover those areas which are of main concern in the design and operation of pulsed high-power iodine lasers.