The Bradsher reaction has been so extended since 1940, that it now, in many instances, is the method of choice for the preparation of Polycylic aromatic compounds. This is largely because the yields are higher than in the Pschorr and Elbs reactions, and because no rearrangement occurs. The present review article deals with the cyclodehydration reaction of aromatic ketones, aldehydes and imines in the preparation of Phenanthrene, Anthracene and some heterocylic systems. The mechanism of such cyclode-hydrations is also discussed in detail.