Oral cancer represents a significant and growing concern worldwide due to its high prevalence. Early detection of neoplastic changes in the oral mucosa is the preeminent method to improve survival rates and quality of life of patients, because at these embryonic stages their eradicative treatment measures would be immense and more effective. Currently, most accepted clinical procedure for detection of oral cancer involves visual inspection and ensuing biopsy guided histological analysis, which is considered as "gold standard." However, this intact procedure is subjective, time consuming, agonizing and costly. Consequently, exploration of new techniques for early diagnosis of oral cancer assume great significance, which are often known as "optical biopsies." However, development of such an optimal cost-effective optical system with adequate diagnostic accuracies for clinical application is still a challenge. This book presents an overview on basics of cancer, light-tissue interaction concepts and a critique. Moreover, it explores some innovative optical approaches for early detection of oral cancer in a clinical environment.