This book helps in understanding the relationship between microorganisms and oral carcinogenesis, and the possible oncogenic mechanisms enhancing the association. The book highlights the association between oral cancer, primarily oral squamous cell carcinoma (OSCC), a major global health problem with high incidence and low survival rates with infection and inflammation. Establishing the association of the oral microbiome with cancer risk may lead to significant advances in the understanding cancer etiology, potentially opening a new research paradigm for cancer prevention. The book takes the readers through interesting topics such as the epidemiology and etiology of OSCC, the hallmarks of cancer, and the role of inflammation in OCSS. It presents the difference between the normal and diseased oral microbiome. It further describes the carcino-pathogenesis of various groups. Finally, it discusses the clinical correlation of the observations and what the future looks like forthis area of research. The book is interesting for medical students, researchers and clinicians, alike. The knowledge from the book can be exploited practically and used for designing further experiments.