Lichen planus, one of the most common dermatologic immunopathological disease to affect the oral mucous membrane, is a chronic, inflammatory, mucocutaneous disorder of undetermined etiology. Over the last few years there has been a lot of controversy over the possible association of oral lichen planus with various chronic liver diseases. This book presents a simplified pathogenesis for Oral Lichen Planus and revisits its association especially the erosive variant with underlying liver disease using serum transaminase as a diagnostic marker. It also has a detailed compilation on the recent review on its etiopathogenesis, update on clinical management that would be of benefit to under graduate, post graduate and post doctoral students.