Head and neck carcinoma is a devastating disease with poor outcome in advanced stages, shows a marked geographic variation in occurrence. It is the sixth most common human cancer, representing 3% of all types of cancer. They are located in the oral cavity in 48% of cases, and 90% of these are oral squamous cell carcinoma. Therefore, is one of the major global threats to public health.The most desirable way of eliminating the impact of cancer in humans is by prevention.Chemoprevention of cancer aims to prevent, arrest, or reverse either the initiation phase of carcinogenesis or the progression of neoplastic cells to cancer. This book mainly focuses on concepts of carcinogenesis, various aspects of chemoprevention and describes important chemopreventive agents and design of chemopreventive trials.