Always been an enigmatic entity, Odontogenic Keratocyst (OKC) is an epithelial developmental cyst, derived from enamel organ or dental lamina. In the earlier literature, OKC was described as a cholesteatoma (Hauer, 1926; Kostecka, 1929), with the first account of the lesion given by Mikulicz who, in 1876, described it as a dermoid cyst. This book attempts to provide a latest comprehensive review of OKC.